Forcing Patentee Claims
Tun-Jen Chiang †
One of the oddest features of the patent system is that
it allows—indeed requires—patentees to write the
“claims” of their own patent and thereby define their
own monopoly rights. On its face, this arrangement
allows self-interested patentees to aggrandize their
rights over the public and claim more than their
actual invention.
The results have been frequently recognized and
criticized: numerous scholars have argued that
patent claims fail to reflect the real invention and
thereby cause uncertainty in patent rights. But no one
has clearly identified the cause of the problem as the
institutional allocation of drafting responsibility to
patentees; the critiques instead usually blame the
inherent ambiguity of claim language. Consequently,
no one has asked why the patent system permits
patentees to draft claims, when the incentives for
abuse are seemingly obvious.
This Article asks the question and then attempts an
answer. Patentee-written claims are socially valuable,
even though they systematically cover more than the
actual invention, because courts do not have enough
information to determine what the actual invention is
from scratch. Requiring patentees to write claims
forces them to divulge an approximation of the actual
invention, which courts can then more meaningfully
evaluate for accuracy. While patentees will over-claim,
they cannot over-claim too much, and an imperfect
approximation of the actual invention is better than
having a court or the PTO make an uninformed
guess on the correct scope of the patent. The Article
then explains the implications of this insight for the
long-running debate over how claims should be
construed and applied in patent litigation.
Assistant Professor of Law, George Mason University School of Law.
Thanks to Michael Abramowicz, Jonas Anderson, Tom Baker, Michelle
Boardman, Sam Bray, Michael Carroll, Eric Claeys, Lloyd Cohen, Jorge
Contreras, Bruce Kobayashi, Peter Lee, Mark Lemley, Oskar Liivak, Gregory
Mandel, Adam Mossoff, Lisa Larrimore Ouellette, Josh Wright, and
participants at the IP Scholars Conference, the Manne Faculty Forum, and
the Workshop at American University for comments.
†
1
INTRODUCTION .........................................................................................2
I.
THE PUZZLE OF PATENTEE-DRAFTED CLAIMS ..................................6
A. Background on the Patent Document........................................6
1.
The specification describes an embodiment............................6
2.
The claim delineates monopoly scope. ....................................7
B. The Problematic Allocation of Claim Drafting..........................9
C. The Criticisms of the Literature ..............................................12
1.
Dan Burk and Mark Lemley .................................................13
2.
Oskar Liivak ..........................................................................14
3.
Chris Cotropia........................................................................15
4.
Peter Lee ................................................................................15
5.
Robert Merges and John Duffy .............................................16
6.
Judge S. Jay Plager ...............................................................17
II. THE INFORMATION-FORCING FUNCTION OF CLAIMS ......................19
A. An Analogy: The Value of Contracts of Adhesion ...................19
B. Courts Lack Information About the Real Invention ...............21
1.
The misconception of the invention as an embodiment. ......21
2.
The problem of identifying the inventive idea......................23
3.
The impossibility of direct determination.............................25
C. Claims Force Information from Patentees ..............................27
D. The Imperfection of Claims and Ex Post Adjustment ............31
III. IMPLICATIONS FOR THE CLAIM CONSTRUCTION DEBATE ................33
A. Short-run Efficiency: Equal Weight to All Evidence ..............35
B. Long-run Incentives: More Weight to Claim Text ..................37
C. Balancing Long-run and Short-run Efficiency ........................40
IV. ADDRESSING THE LINGUISTIC INDETERMINACY OBJECTION ..........42
A. The Circular Nature of the Objection. .....................................43
B. Under-determinacy Versus Indeterminacy. ............................52
CONCLUSION ..........................................................................................54
INTRODUCTION
One of the oddest features of the patent system is that patentees get
to define their own monopoly rights by writing the claims of their
patent. 1 Quite obviously, self-interested patentees will write the claims
in a way that aggrandizes their rights to the detriment of the public.
Equally obviously, it is impossible for the Patent and Trademark Office
(PTO) to police patentees so fully as to detect every subtle drafting
trick. 2 In other words, control over claim drafting gives patentees at
See 35 U.S.C. § 112 ¶ 2 (2006) (requiring patentees to write claims);
Universal Oil Prods. Co. v. Globe Oil & Refining Co., 322 U.S. 471, 484 (1944)
(“The claim is the measure of the grant.”).
2 See Dan L. Burk & Mark A. Lemley, Fence Posts or Sign Posts?
Rethinking Patent Claim Construction, 157 U. PA. L. REV. 1743, 1752–53
(2009) (arguing that patent applicants intentionally include ambiguities in
1
2
least some ability to cover more than the actual invention to which
they are entitled.
The fact that claims are written in an overbroad manner underlies
two frequently-observed problems in the patent system. First, broadlywritten claims cause overbroad monopolies that harm competition. 3
Second, patent claims that are written in broad and abstract language
cause legal uncertainty. 4
In the existing literature, these problems are often attributed to the
inherent ambiguity of claim language. 5 But, as Lawrence Solum and I
have previously explained, linguistic ambiguity is rarely the cause of
problems in patent law today. 6 Rather, much of the criticism of patent
claims can be better understood as implicitly criticizing the
institutional allocation of claim drafting. That is, the real problem with
patent claims is not that they are incomprehensible, but that they
clearly and comprehensibly cover more than the real invention. And
claims cover more than the real invention because the patentees who
draft them have incentives to over-claim. No one has explicitly
questioned the institutional allocation of claim drafting to patentees
claim language); Mark A. Lemley, Rational Ignorance at the Patent Office, 95
NW. U. L. REV. 1495, 1528 (2001) (“Examiners do not in fact spend long hours
poring over a patent application.”).
3 See, e.g., FEDERAL TRADE COMMISSION, TO PROMOTE INNOVATION: THE
PROPER BALANCE OF COMPETITION AND PATENT LAW AND POLICY 5,
http://www.ftc.gov/os/2003/10/innovationrpt.pdf (stating that “questionable
patents” containing overbroad claims “are a significant competitive concern”).
4 See JAMES BESSEN & MICHAEL J. MEURER, PATENT FAILURE: HOW
JUDGES, BUREAUCRATS, AND LAWYERS PUT INNOVATORS AT RISK 199–200
(2008) (arguing that abstract claim language causes uncertainty); Kimberly A.
Moore, Markman Eight Years Later: Is Claim Construction More Predictable?,
9 LEWIS & CLARK L. REV. 231, 233, 239 (2005) (reporting a 34.5% reversal
rate for claim construction); Gretchen A. Bender, Uncertainty and
Unpredictability in Patent Litigation: The Time is Ripe for a Consistent Claim
Construction Methodology, 8 J. INTELL. PROP. L. 175 (2001).
5 See infra Part IV (discussing the linguistic indeterminacy thesis). See
also Autogiro Co. v. United States, 384 F.2d 391, 396 (Ct. Cl. 1967) (arguing
the problem arises because “[c]laims cannot be clear and unambiguous on
their face”); BESSEN & MEURER, supra note 4, at 57 (arguing the problem
arises because “the Patent Office does a poor job of monitoring the clarity of
patent claims”); Peter S. Menell et al., Patent Claim Construction: A Modern
Synthesis and Structured Framework, 25 BERKELEY TECH. L.J. 711, 716
(2010) (“If nothing else, the past two decades revealed the inherent
difficulties of using language to define the boundaries of abstract and
intangible rights.”).
6 Tun-Jen Chiang & Lawrence B. Solum, The Interpretation Construction
Distinction in Patent Law, 123 YALE L.J. (forthcoming 2013).
3
because the literature has been too focused on the linguistic ambiguity
thesis. 7 Once we understand the true problem, however, the question
that naturally arises is why the patent system gives the power of
drafting to patentees rather than some less-biased party such as the
PTO or a court.
This Article provides an answer: A key premise of the patent system
is that the government (including the judiciary) does not have enough
information to directly determine what the socially optimal reward for
a patentee is. 8 Claims force patentees, who have superior information, 9
to disclose an approximation of the optimal monopoly scope, and this
disclosure furnishes courts and the PTO with a starting baseline to
scrutinize. The only alternative to relying on patentee-drafted claims
to provide an initial baseline is for courts or the PTO to take an
uninformed guess in the first instance, which will result in even
greater errors. 10 While patentee-drafted claims are surely imperfect,
they are better than the stab-in-the-dark alternative. 11
This insight has important implications for the long-running debate
on claim construction. Many commentators have argued that, because
claim text often does not describe the real invention, courts should use
their interpretative powers to overcome this defect. 12 In its extreme
form, the argument says that courts should abolish claims altogether
and look only at external evidence (i.e. evidence outside the claim) to
determine the real invention. 13 In a lesser form, the argument is that,
Id.
Louis Kaplow, The Patent-Antitrust Intersection: A Reappraisal, 97 HARV.
L. REV. 1813, 1844 (1984).
9 Clarisa Long, Information Costs in Patent and Copyright, 90 VA. L. REV.
465, 496-97 (2004).
10 A common counterargument is that the patent specification can provide
courts with all the information that they need to discern the real invention.
For why this is not correct, see Part II.B.1.
11 See Keystone Bridge Co. v. Phoenix Iron Co., 95 U.S. 274, 278 (1877)
(stating that, before the development of patentee-written claims, courts
ascertained the invention “by inference and conjecture”).
12 See, e.g., Burk & Lemley, supra note 2, at 1785; Dan Burk, Dynamic
Claim Interpretation, in INTELLECTUAL PROPERTY AND THE COMMON LAW
(Shyam Balganesh, ed., forthcoming 2012), available online at
http://ssrn.com/abstract=2005251; Oskar Liivak, Rescuing the Invention from
the Cult of the Claim, 42 SETON HALL L. REV. 1, 40–42 (2012); Peter Lee,
Substantive Claim Construction as a Patent Scope Lever, 1 IP THEORY 100,
105 (2010); Chris Cotropia, Patent Claim Interpretation Methodologies and
Their Claim Scope Paradigms, 47 WM. & MARY L. REV. 49, 127 (2005). See
also infra Part I.C.
13 See, e.g., Burk & Lemley, supra note 2, at 1784–85 (arguing for claims to
be abolished).
7
8
4
although courts need not abolish claims, they nonetheless should give
external evidence greater weight in the interpretative calculus in order
to compensate for the patentee’s drafting bias and get the most
accurate determination of the real invention. 14 As the Article will
explain, both of these arguments turn the problem on its head: the
critics implicitly assume that courts can reliably discern the real
invention (a.k.a. “the optimal patent scope” 15 ) without claims, but the
whole reason for requiring claims in the first place is that courts do not
have this capacity and need an information-forcing mechanism.
The initial implication of the information-forcing insight is that
courts should not abolish claims altogether and attempt to directly
discern optimal patent scope; such a methodology faces a problem of
insurmountable information costs. But it means more: if courts did not
give claim text any more weight in claim construction than other types
of evidence, then patentees would have no incentive to spend money to
draft claims. 16 The long-run result would be de facto abolition, which
would once again increase judicial information costs and force courts to
take uninformed guesses on the correct scope of the patent.
The result of this analysis is that courts must engage in a delicate
balance between two competing considerations. Supplementing the
claim text with external evidence will generate better outcomes in the
short run, as courts can use the external evidence to detect and rectify
a particular patentee’s drafting bias. But courts cannot rely too heavily
on external evidence; they must give appropriate weight to claim text
in order to provide patentees with a long-run incentive to write claims.
And such a balanced approach is in fact descriptive of real life, where
courts give primary weight to claim text—by treating the written claim
as a presumptive baseline for patent scope—but also do not exclude
external evidence from the analysis completely. 17 The Article therefore
provides a normative and positive theory for how courts should (and
do) construe claims, in addition to answering the predicate question of
why the patent system assigns the task of claim drafting to patentees.
See, e.g., Lee, supra note 12, at 106 (“extrinsic evidence . . . provides a
more accurate description of the technological scope of a patented invention”).
15 See infra Part II.B.1 (defending the proposition that the real invention is
conceptually equivalent to the optimal scope of the patent).
16 See Eric Posner, The Parol Evidence Rule, the Plain Meaning Rule, and
Principles of Contract Interpretation, 146 U. PA. L. REV. 533, 544 (1998)
(demonstrating this point in the field of contract law).
17 Compare Merrill v. Yeomans, 94 U.S. 568, 570 (1876) (claim text is “of
primary importance”) with Autogiro Co. v. United States, 384 F.2d 391, 397
(Ct. Cl. 1967) (“In deriving the meaning of a claim, we inspect all useful
documents . . . .”).
14
5
The Article proceeds in four Parts. Part I provides a background and
describes the puzzle of allowing patentees to write the patent’s claims,
as well as the adverse consequences (and implicit criticisms) that this
allocation of drafting responsibility has produced. Part II then explains
why the allocation of drafting responsibility to patentees is an efficient
mechanism to solve an underlying information problem. Part III
elaborates on a key implication of the theory—namely, in order to
provide an incentive for patentees to draft claims and to convey
information, courts must give claim text some weight over external
evidence, a position that contradicts many academic proposals. Part IV
addresses the common objection that claim language is inherently
indeterminate. A brief conclusion then follows.
I. THE PUZZLE OF PATENTEE-DRAFTED CLAIMS
A. Background on the Patent Document
A United States patent is a complex document, but its two most
important parts are the specification and the claims. 18 Both the
specification and the claims are drafted by the patentee, and both are
supposed to describe the patentee’s invention. 19 But although the
statute uses the word “invention” in both of these contexts, they refer
to two very distinct concepts. As this Section will explain, the
specification describes an invention in the sense of an embodiment,
while the claim describes an invention in the sense of monopoly scope.
1.
The specification describes an embodiment.
In simplified terms, the specification is the portion of the patent
where technical knowledge about the invention is provided to the
public. It is obviously important that the disclosure be sufficiently
detailed that the public can gain the full benefit of the invention once
the patent expires. 20 Section 112 of the patent statute accordingly
mandates that the specification “contain a written description of the
invention, and of the manner and process of making and using it, in
such full, clear, concise, and exact terms as to enable any person
skilled in the art . . . to make and use the same.” 21
In conventional patent parlance, the two major components of a patent
are known as the “specification” and the “claims.” CRAIG ALLEN NARD, THE
LAW OF PATENTS 39 (2008). In the patent statute, however, what is commonly
called the specification is instead called the “written description,” while the
word “specification” is used to denote the combination of the written
description and the claims. Id.; see 35 U.S.C. § 112 (2006). I will follow the
conventional usage in this Article.
19 35 U.S.C. § 112 (2006).
20 Kewanee Oil Co. v. Bicron Corp., 416 U.S. 470, 480–81 (1974).
21 35 U.S.C. § 112 (2006).
18
6
In practical terms, what this means is that the specification
describes an embodiment. 22 Only tangible embodiments can be “made,”
and so the statute implicitly conceptualizes the “invention” of the
specification in these terms. Similarly, the requirement that the
specification description be detailed and “exact” reflects a conception of
the invention as a tangible embodiment whose precise features can be
specified.
For example, the Wright brothers could not have simply written in
their patent specification that they had invented “a flying machine
with wings.” Such an abstract description would have been too sparse
to satisfy the requirements of section 112. 23 Rather, the Wright
brothers had to specify that their particular airplane embodiment had
a wooden frame and cloth wings, and that it was controlled using rope
pulleys, and numerous other details about their particular wooden
glider. 24 Such a concrete and detailed description is important to the
patent system in order to ensure that the public has all the technical
details it needs to reproduce the patentee’s embodiment in the future.
2.
The claim delineates monopoly scope.
Although it is important that patentees provide lots of technical
detail about their invention, the law has also long recognized that
patent scope cannot be limited to literal replication of the specification
embodiment. 25 The reason is copyists will quickly take the patentee’s
core idea but make minor changes to the details, and thereby escape
infringement. 26 For example, the inventor of the table (back in the
Stone Age) might teach a particular table embodiment made of wood,
See Smith v. Snow, 294 U.S. 1, 11 (1935) (statute requires describing one
embodiment, but claims are not limited to the embodiment shown); Autogiro
Co. v. United States, 384 F.2d 391, 398 (Ct. Cl. 1967) (“The specification sets
forth the best mode contemplated by the inventor of carrying out his
invention. This one embodiment of the invention does not restrict the
claims.”).
23 John F. Duffy, Rules and Standards on the Forefront of Patentability, 51
WM. & MARY L. REV. 609, 625 (2009) (“abstraction is the very antithesis of
the precision required by the disclosure provisions of the Patent Act”).
24 See U.S. Patent No. 821,393 (filed Mar. 23, 1903) (Wright brothers’
patent on the airplane).
25 Graver Tank & Mfg. Co. v. Linde Air Prods. Co., 339 U.S. 605, 607
(1950) (arguing that confining protection to the copying of “every literal detail
would be to convert the protection of the patent grant into a hollow and
useless thing”).
26 MARTIN J. ADELMAN ET AL., CASES AND MATERIALS ON PATENT LAW 459
(2d ed. 2003) (“If courts strictly limit the scope of patent protection to the
specific examples disclosed in the specification, competitors could readily
circumvent the patent through minor changes in design.”).
22
7
and he could not teach a plastic table because plastic would not have
been invented. But anyone who saw a wooden table would immediately
understand that a plastic table would work just as well. If the patent
was confined to literal replication of a wooden table, then it would
become worthless as soon as plastic—or any other alternative to
wood—was invented. This would be bad for the social goal of the
patent system in providing incentives for innovation. 27
Thus, rather than confining patent scope to literal replication of the
specification embodiment, patent law has always allowed the monopoly
to extend more broadly to cover the inventive principle. 28 When stated
explicitly, the proposition that patent scope covers an idea (and not an
embodiment) is not controversial, 29 though even experienced patent
lawyers are often confused on this point. 30 The key point is that patent
law has two separate concepts of “the invention,” and the two parts of
the patent are describing entirely different things at a conceptual level.
The specification describes the invention in the sense of a concrete
embodiment. 31 The claim identifies the patentee’s inventive principle
and delineates patent scope. 32
The claim is a single sentence, appearing at the end of the patent,
that identifies the core inventive features that the patentee considers
important. 33 What this means is that claims leave out extraneous
Graver Tank, 339 U.S. at 607.
See, e.g., Pfaff v. Wells Elecs., Inc., 525 U.S. 55, 60 (1998) (“The primary
meaning of the word ‘invention’ in the Patent Act unquestionably refers to
the inventor’s conception rather than to a physical embodiment of that
idea.”); Cont’l Paper Bag Co. v. E. Paper Bag Co., 210 U.S. 405, 418–19 (1908)
(“The principle of the invention is a unit, and invariably the modes of its
embodiment in a concrete invention may be numerous and in appearance
very different from each other.” (quoting 2 WILLIAM C. ROBINSON, THE LAW
OF PATENTS FOR USEFUL INVENTIONS § 485, at 75 (1890))).
29 Id.
30
See infra Part II.B.1. See also EMERSON STRINGHAM, DOUBLE
PATENTING 209 (1933) (“This primitive confusion of ‘invention’ in the sense of
physical embodiment with ‘invention’ in the sense of definition of the
patentable . . . survives to the present day, not only in the courts, but among
some examiners in the Patent Office.”).
31 35 U.S.C. § 112 ¶ 1 (2006).
32 35 U.S.C. § 112 ¶ 2 (2006); Phillips v. AWH Corp., 415 F.3d 1303, 1312
(Fed. Cir. 2005) (en banc) (“It is a bedrock principle of patent law that the
claims of a patent define the invention to which the patentee is entitled the
right to exclude.”).
33 A patent can have more than one claim, if the patentee wants to identify
multiple combinations of features as critical. See 35 U.S.C. § 112 ¶ 2 (2006)
(requiring “one or more” claims).
27
28
8
details. For example, the Wright brothers’ claim to the airplane
identified three key features:
a. adjustable wings
b. a rudder, and
c. adjusting the rudder in tandem with the wings. 34
For present purposes of providing a doctrinal background to patent
claims, the key point is that every product that utilizes these claimed
features is then deemed to infringe the patent, even if the infringing
product looks very different from the specification embodiment and
incorporates later-developed technology that was not disclosed in the
patent specification. 35 For example, a modern Boeing 747 has
aluminum wings with adjustable flaps rather than the Wright
brothers’ flexible cloth wings, and it adjusts its rudder in tandem with
the wings using advanced hydraulics rather than rope pulleys. But the
Boeing 747 still contains all three of the claimed features, and it
therefore infringes the Wright brothers’ patent. 36 In this way, the
claim identifies not a particular wooden glider airplane, but the
general idea of all airplanes that have wings and a coordinated rudder.
The scope of the patent is then defined in these terms. 37
B. The Problematic Allocation of Claim Drafting
It can be seen from the quick introduction that claims play an
outsized role in the modern patent system. Indeed, they are usually
This is a simplified version of their seventh claim. The original (rather
convoluted) language is:
In a flying machine, the combination, with an aeroplane, and
means for simultaneously moving the lateral portions thereof
into different angular relations to the normal plane of the body
of the airplane and to each other, so as to present to the
atmosphere different angles of incidence, of a vertical rudder,
and means whereby said rudder is caused to present to the
wind that side thereof nearest the side of the aeroplane having
the smaller angle of incidence and offering the least resistance
to the atmosphere, substantially as described.
U.S. Patent No. 821,393, col. 6 ll. 62–74 (filed Mar. 23, 1903).
35 See Cont’l Paper Bag, 210 U.S. at 418-19 (“The principle of the invention
is a unit, and invariably the modes of its embodiment . . . may be numerous
and in appearance very different from each other.”).
36 At least it would, if the patent had not already expired. The point is that
it falls within the Wright brothers’ “invention” for patent scope purposes,
even though it is clearly different from their embodiment.
37 See Universal Oil Prods. Co. v. Globe Oil & Refining Co., 322 U.S. 471,
484 (1944) (“The claim is the measure of the grant.”).
34
9
described as the most important part of the patent document. 38 And, as
pointed out above, the patent system needs something like a claim to
serve the function of delineating patent scope: It needs a legal
instrument, separate from the specification, to serve the purpose of
identifying the inventive principle. The question is why the patent
system has chosen a patentee-written claim for this purpose.
The standard response—the one that would reflexively be given by
patent lawyers and judges, and found in virtually every casebook and
treatise—is that claims are given their role in the patent system
because of the notice theory. 39 The notice theory says that patentees
should describe their invention clearly and precisely, so that the public
and competitors can determine whether they infringe the patent. 40 The
benefits of such ex ante notice for competitors and the public (in being
able to plan their business activities) then justifies the outsize role
claims are given in the patent system. 41
The problem is that the notice theory relies on a non-sequitur when
it comes to the allocation of drafting responsibility to patentees. In one
incarnation, the notice theory says that patentees have the obligation
to describe the invention accurately and precisely in writing the
claim. 42 In another incarnation, it says that claims are given their
outsized role in the patent system because they actually do describe
the real invention. 43 What the notice theory never explains is why
patentees would actually comply with their obligation and write claims
that actually describe the real invention, when it is manifestly
contrary to the patentee’s self-interest to do so.
John F. Duffy, On Improving the Legal Process of Claim Interpretation:
Administrative Alternatives, 2 WASH. U. J.L. & POL’Y 109, 109 (2000); see In
re Hiniker Co., 150 F.3d 1362, 1369 (Fed. Cir. 1998) (“the name of the game is
the claim”); Mark A. Lemley, The Changing Meaning of Patent Claim Terms,
104 MICH. L. REV. 101, 101 (2005) (“The claims of a patent are central to
virtually every aspect of patent law.”).
39 See, e.g., Permutit Co. v. Graver Corp., 284 U.S. 52, 60 (1931) (claims
“inform the public during the life of the patent of the limits of the monopoly
asserted, so that it may be known which features may be safely used or
manufactured without a license and which may not”).
40 Merrill v. Yeomans, 94 U.S. 568, 573–74 (1876) (“nothing can be more
just and fair, both to the patentee and to the public, than that the former
should understand, and correctly describe, just what he has invented”).
41 Haemonetics Corp. v. Baxter Healthcare Corp., 607 F.3d 776, 781 (Fed.
Cir. 2010) (“Patent claims function to delineate the precise scope of a claimed
invention and to give notice to the public, including potential competitors, of
the patentee's right to exclude.”).
42 Merrill, 94 U.S. at 573–74.
43 Haemonetics, 607 F.3d at 781.
38
10
Once we consider a rational self-interested patentee’s actual
incentives, it becomes obvious that patent claims in real life will not
describe the real invention. Rather, patentees will draft claims to cover
as much as they can possibly get away with. 44 To be sure, patentees
cannot claim everything in the universe, because the PTO will
scrutinize the claims; 45 but it is fanciful to suppose that the PTO can
police patentees perfectly and catch every subtle drafting trick. 46 If the
goal is to identify the inventive principle using a textual instrument, it
would appear that a textual instrument written by a less-biased party
(e.g. the PTO examiner) would be more accurate and less subject to
gamesmanship. And the fact that patentees have the incentive and
ability to over-claim then leads to two well-documented problems in
the patent system. The first is that claims are systematically
overbroad. 47 The second is that courts applying those claims render
highly unpredictable decisions. 48
I will describe the literature that documents these problems in the
next Section. But, before that, it is important to note here that the
uncertainty problem is traceable to the fact that patentee drafted
claims are overbroad, even though the causal link might not seem
obvious at first blush. The fact that patentee-drafted claim text is often
overbroad means that courts will naturally try to compensate for this
by construing the language down, in order to reach an outcome more
closely corresponding to the actual invention. 49 A good example is
ASH TANKHA ET AL., PATENT YOUR IDEA 34 (2011) (“The claims should be
drafted as broadly as possible but just narrower than the prior art.”).
45 35 U.S.C. § 131 (2006) (requiring PTO examination).
46 See BESSEN & MEURER, supra note 4, at 57 (arguing the PTO lacks
resources to police patentees); Lemley, supra note 2, at 1528 (same).
47 Federal Trade Commission, supra note 3, at 5.
48 See, e.g., Kimberly A. Moore, Are District Court Judges Equipped To
Resolve Patent Cases?, 15 HARV. J.L. & TECH. 1, 2–4 (2001) (arguing that
reversal rate is too high); David L. Schwartz, Practice Makes Perfect? An
Empirical Study of Claim Construction Reversal Rates in Patent Cases, 107
MICH. L. REV. 223 (2008) (finding that judicial experience does not increase
predictability); Kristen Osenga, Linguistics and Claim Construction, 38
RUTGERS L.J. 61, 90 (2006) (finding that disputes frequently arise even with
non-technical terms); Andrew T. Zidel, Patent Claim Construction in the Trial
Courts: A Study Showing the Need for Clear Guidance from the Federal
Circuit, 33 SETON HALL L. REV. 711, 712–15 (2003).
49 See, e.g., Eibel Process Co. v. Minn. & Ont. Paper Co., 261 U.S. 45, 63
(1923) (“In administering the patent law, the court first looks into the art, to
find what the real merit of the alleged discovery or invention is . . . , to secure
to the inventor the reward he deserves.”); Retractable Techs., Inc. v. Becton,
Dickinson & Co., 653 F.3d 1296, 1305 (Fed. Cir. 2011) (“In reviewing the
44
11
Nystrom v. TREX Co., Inc., 50 where the patentee drafted a claim that
facially covered all “boards” used for flooring. The court, however,
interpreted the claim to cover only wooden boards that are cut from a
log (and excluding, for example, composite boards), 51 in order to adjust
for the patentee drafting bias. Such departures from plain text, in turn,
create uncertainty. My point right now is not to praise or condemn this
judicial reaction to overbroad claims, it is to point out that this judicial
reaction and its associated uncertainty arises in part because of the
allocation of drafting responsibility to patentees.
C. The Criticisms of the Literature
The misalignment of patentee drafting incentives leads to a variety
of problems for the real life patent system, which the literature has
exhaustively described. By and large, the literature has not diagnosed
the underlying problem as being that patent claims are drafted by
patentees, and thus are intentionally overbroad. Rather, in the
conventional literature, the problem is framed in terms of saying that
text—including but not limited to claim text—is inherently
indeterminate, so that the problem lies not with patentee intentions
but with a false and misplaced faith in the ability of text to accurately
delineate legal rights. 52 As I will explain later in Part IV, this
fundamental disagreement about the underlying cause of the problem
is an important reason why the critics and I diverge significantly
regarding the proper solution.
At this stage, however, the point is that the critics and I agree on
the overt manifestations that indicate an underlying problem, namely:
(1) real-life claims frequently do not describe the patentee’s actual
invention, and (2) there is significant uncertainty in claim construction
litigation. Both of these outward problems are fairly traceable to the
patent system’s reliance on patentee-drafted claims (regardless of
whether it is because claims are drafted by patentees, or whether it is
because claims exist at all). Therefore, in the absence of any good
explanation for why the patent system relies on patentee-drafted
claims, the seeming policy solution is to abolish claims. This solution is
what almost everybody in this literature advocates either de jure or de
facto. A sampling of the literature follows.
intrinsic record to construe the claims, we strive to capture the scope of the
actual invention.”).
50 424 F.3d 1136 (Fed. Cir. 2005).
51 Id. at 1143–45.
52 See infra Part IV. See also Pac. Gas & Elec. Co. v. G.W. Thomas Drayage
& Rigging Co., 442 P.2d 641, 643–44 (Cal. 1968) (arguing against “a primitive
faith in the inherent potency and inherent meaning of words”).
12
1.
Dan Burk and Mark Lemley
Perhaps the most prominent critics of patent claims are Dan Burk
and Mark Lemley. In an article titled Fence Posts or Sign Posts:
Rethinking Patent Claim Construction, Burk and Lemley argue that
the modern claiming system “isn’t working.” 53 They begin by
describing how claim construction is highly unpredictable, and how
claims accordingly provide little ex ante notice to competitors:
Patent law has provided none of the certainty associated
with the definition of boundaries in real property law.
Literally every case involves a fight over the meaning of
multiple terms, and not just the complex technical ones.
Recent Federal Circuit cases have had to decide plausible
disagreements over the meanings of the words “a,” “or,”
“to,” “including,” and “through,” to name but a few. Claim
construction is sufficiently uncertain that many parties
don't settle a case until after the court has construed the
claims, because there is no baseline for agreement on
what the patent might possibly cover. 54
Although Burk and Lemley devote considerable space to criticizing
the unpredictability of claims and the associated litigation costs, they
argue that it is not the biggest problem. The biggest problem, they say,
is that a focus on claim text drafted by the patentee’s lawyers detracts
from an inquiry into the real invention:
Far more significant is that legal interpretation of words
has taken the place of a definition of the proper scope of
the invention itself. . . . It should be no surprise that the
result of this collateral process bears only a coincidental
relationship to the ideal scope of the patent claim. After
Markman, we're not often litigating what the inventor did
or what her patent should cover, because we are too
concerned with what the lawyers did to define what the
invention should cover. We have, in other words, taken
our eyes off of the ball. 55
After describing these failures of modern claiming, Burk and Lemley
argue that we should abolish claims. 56
Burk & Lemley, supra note 2, at 1744.
Id. at 1744–45.
55 Id. at 1762.
56 Id. at 1784.
53
54
13
2.
Oskar Liivak
Even more scathing than Burk and Lemley is Oskar Liivak, who has
written an article titled Rescuing the Invention from the Cult of the
Claim. 57 As the title suggests, Liivak argues that the patent system’s
reliance on the claim is akin to a cult-like delusion. In Liivak’s view,
the “cult of the claim” commits (at least) two grave errors.
First, Liivak argues that “the invention is a substantive, technical
concept.” 58 Liivak argues that this substantive conception of the
invention is the more appropriate framework to consider issues of
patent scope, and that current law has improperly ignored this
substantive conception of the invention in favor of a “meaningless”
cult-like devotion to claim text. 59 Like Burk and Lemley, therefore,
Liivak argues that a focus on claims takes our eyes of the ball (of the
real, substantive, invention).
Second, Liivak argues that a cult-like focus on claims results in
confusion and uncertainty. He states: “Courts seem unable to agree on
what particular patent claims mean. The promise of certainty made by
peripheral claiming appear to be an illusion. In short, the modern
peripheral claiming system isn't working.” 60
What Liivak concludes from these premises is that courts should
focus on the real substantive invention. 61 Unlike Burk and Lemley, he
does not advocate abolishing claims as a formal matter, but rather
advocates a rule that courts should always “interpret” claim language
to cover the “set of embodiments disclosed in the specification.” 62 As a
practical matter, however, Liivak’s approach would make claims a
dead letter. The real inquiry for patent scope becomes not what the
claim says, but what “set of embodiments disclosed in the specification”
a court will find.
Liivak resists the conclusion that his proposal renders claims a dead
letter. In his article, Liivak argues that claims continue to have a role
under his theory because courts would continue to follow the text
“[w]hen the claims precisely and accurately reflect the invention.” 63
But this is a completely empty standard: If courts follow claim text
only after first determining that it matches the real invention, then
Liivak, supra note 12.
Id. at 5.
59 Id. 40.
60 Id. at 37 (internal quotations and alterations omitted).
61 Id. at 5 (arguing that we should employ a “substantive interpretation of
the invention . . . to structure our patent system”).
62 Id. at 44.
63 Id. at 43.
57
58
14
logically they must first determine what the real invention is, and that
inquiry would be doing all the analytical work. The claim text would be
a mere post-hoc rationalization for the pre-determined result.
3.
Chris Cotropia
Also making a similar argument is Chris Cotropia. According to
Cotropia, existing patent law operates largely on a view that “the claim
is the invention.” 64 This means that courts attach a “heavy
presumption” that patent scope is determined by the text of the
claim. 65 Cotropia argues that this approach is contrary to “basic patent
theory” because it “invites disjointedness between protection and the
real-world contributions of the inventor.” 66
In place of the focus on patent claims, Cotropia argues that patent
scope should be defined primarily by what he calls the “external”
invention. 67 In practical terms, Cotropia argues that the external
invention is primarily found by looking at the patent specification. 68
Like Liivak, Cotropia would retain claims as a formal matter, but
argues that they should be creatively “interpreted” to match the
specification disclosure. 69 Once again, the claim text itself becomes
secondary in such a regime.
4.
Peter Lee
Peter Lee has also argued that claims are defective because they do
not describe the real invention—what Lee calls the “substantive
technological contribution”—and also cause significant uncertainty.
According to Lee:
These days, entire claim construction disputes revolve
around the meaning of words such as “a.” Such a
textualist, inward-looking approach to claim construction
deprioritizes contextual factors such as expert testimony
and industry dynamics that speak to an invention’s
substantive technological contribution. This literalist
claim construction methodology, moreover, cannot even
assert the virtues of certainty and predictability. Claim
Christopher A. Cotropia, What is the “Invention”?, 53 WM. & MARY L.
REV. 1855, 1886 (2012).
65 See id. at 1897 & n. 223 (citing Cotropia, supra note 12, at 123–24).
66 Id. at 1862 & 1897.
67 Id. at 1895 (“The external invention falls more in line with the incentiveto invent narrative.”).
68 Id. at 1906 (“choosing an external definition of the invention means the
specification plays a heavy role”).
69 Id. (“Because claims must be read in light of the specification, the
disclosure dictates claim meaning.”).
64
15
construction after Phillips is still marred by high reversal
rates and significant internal dissent among judges of the
Federal Circuit. 70
Somewhat unlike the other critics, Lee’s proposed solution does not
focus too much on using the patent specification to determine patent
scope. Instead, he argues that courts should look to “expert testimony
and industry dynamics.” 71 What this essentially amounts to is expert
testimony and even more expert testimony, because “industry
dynamics” would presumably need to be conveyed through expert
witnesses. More importantly, like the other critics, Lee’s proposal
renders claims a dead letter, because what matters is not what the
claim says, but what the expert witnesses say about the patentee’s
“substantive technological contribution.”
Like many others, Lee resists this conclusion. In his article, Lee
argues that his proposal would not render claims dead letter because
he includes an exception that courts would be obliged to give effect to
the claim text if claim construction case law (note, not the text itself)
gave a clear answer to the infringement dispute. 72 But this is a hollow
exception, for two reasons. First, as Lee himself explains, current claim
construction case law is already so uncertain that it basically never
gives a clear answer. 73 Second, even if claim construction case law
today gives clear answers in some cases, Lee’s methodology would
itself generate a body of claim construction case law where courts bend
claim text in ever-more-creative ways to achieve the substantive
invention. Over the long run, claim construction case law would
therefore become less clear, and the vicious cycle would continue until
no clear answers remained. 74
5.
Robert Merges and John Duffy
In their leading casebook on patent law, Robert Merges and John
Duffy repeat the basic critique that patent law has “los[t] sight of [the]
invention.” 75 According to Merges and Duffy, patent law today focuses
excessively on text, and the reliance on text means that courts often
Lee, supra note 12, at 104 (emphasis added).
Id.
72 Id. at 113 (“it bears emphasizing that under my proposal, substantive
and policy considerations only come into play when traditional claim
construction does not yield a clear answer”).
73 Id. at 102–04, 114 (arguing that claim construction is “inherently
difficult to perform,” “fraught with indeterminacy,” “highly indeterminate,”
and has “well known difficulties”).
74 See infra Part IV.A (explaining this self-reinforcing cycle).
75 ROBERT PATRICK MERGES & JOHN FITZGERALD DUFFY, PATENT LAW AND
POLICY: CASES AND MATERIALS 819 (5th ed. 2011).
70
71
16
adjudicate patent scope “without any of the judges knowing what the
inventor’s alleged contribution to the art is.” 76
Instead of a textualist procedure, Merges and Duffy argue that
courts should “first look into the art to find what the real merit of the
alleged discovery or invention is and whether it has advanced the art
substantially.” 77 If the patentee has made a large social contribution,
the court would then be “liberal in its construction of the patent to
secure to the inventor the reward he deserves,” while “being more
stingy if what the inventor has done works only a slight step
forward.” 78 Thus, rather than claim text, the real driver of patent scope
would again be the court’s predicate assessment of the patentee’s
contribution.
6.
Judge S. Jay Plager
It should be no surprise that, given the strong academic tide, the
same argument has gained significant traction among Federal Circuit
judges. A recent concurring opinion by Judge Plager of the Federal
Circuit encapsulates the same basic argument:
However much desired by the claim drafters, who want
claims that serve as business weapons and litigation
threats, the claims cannot go beyond the actual invention
that entitles the inventor to a patent. For that we look to
the written description. I have written elsewhere about
the curse of indefinite and ambiguous claims, divorced
from the written description, that we regularly are asked
to construe, and the need for more stringent rules to
control the curse. 79
In this short paragraph, Judge Plager can be seen to make three
arguments. First, he argues that patentee-drafted claim text—which
expresses their “desires”—often does not describe their actual
inventions, because these drafters have self-interested motives to
obtain undeserved business weapons and litigation threats. Second, he
argues that reliance on claim text causes frequent litigation that the
courts are “regularly” required to resolve. Third, he argues the solution
to both of these problems is to look primarily to the patent specification
Id.
Id. at 820 (quoting Eibel Process Co. v. Minn. & Ont. Paper Co., 261 U.S.
45, 63 (1923) (internal alterations omitted)).
78 Id.
79 Retractable Techs., Inc. v. Becton, Dickinson & Co., 653 F.3d 1296, 1311
(Fed. Cir. 2011) (Plager, J., concurring).
76
77
17
(what Judge Plager calls “the written description” 80 ) to find the actual
invention and to determine patent scope. As should be obvious, these
arguments mirror the general academic argument in substance. And
although this is only a concurring opinion, the same line of thought—
albeit less overtly expressed—can be found in more authoritative case
law as well. 81
Of course, the Federal Circuit is nowhere close to abolishing or
ignoring claims as a matter of actual doctrine. Even Judge Plager
would surely not go that far if directly presented with the question.
But abolition is the logical conclusion of the theoretical argument he is
making. All of the critics, with the notable exception of Burk and
Lemley, shy away from advocating formal abolition. But they do so not
because they see any principle to justify patent claims—there is no
suggestion in any of the critics’ articles on how claims might have
social value when they do not describe the real invention. Instead, the
critics seem to shy away from advocating formal abolition only because
lawyers hate overt change 82 and it is an enormous practical hassle to
persuade Congress to amend the patent statute to abolish the
requirement for formal claiming. 83
In sum, patentee-written claims provide a significant puzzle, with
important real-world consequences. What possible justification is there
for giving a strong role to a legal instrument that does not accurately
describe the real invention, and that causes litigation uncertainty? In
the next Part, I will explain the overlooked reason for allowing—
indeed requiring—patentees to write claims.
Judge Plager is following the more precise usage of the patent statute.
See supra note 18.
81 See, e.g., Retractable Techs., Inc. v. Becton, Dickinson & Co., 653 F.3d
1296, 1305 (Fed. Cir. 2011) (Lourie, J., for the court) (“In reviewing the
intrinsic record to construe the claims, we strive to capture the scope of the
actual invention . . . .”); Kinetic Concepts, Inc. v. Blue Sky Med. Group, Inc.,
554 F.3d 1010, 1019 (Fed. Cir. 2009) (limiting a claim to treating a “wound”
to treatments of skin wounds, because doing otherwise would “expand the
scope of the claims far beyond anything described in the specification”);
Autogiro Co. v. United States, 384 F.2d 391, 397 (Ct. Cl. 1967) (“An invention
exists most importantly as a tangible structure or a series of drawings. A
verbal portrayal is usually an afterthought . . . .”).
82 See generally 1 BRUCE ACKERMAN, WE THE PEOPLE: FOUNDATIONS 17–
18 (1991) (describing the “Burkean sensibility” that is “pronounced amongst
practicing lawyers and judges”); Larry D. Kramer, The Pace and Cause of
Change, 37 J. MARSHALL L. REV. 357, 357 (2004) (“Lawyers hate change.”).
83 See Burk & Lemley, supra note 2, at 1747 (“Central claiming would be a
radical change, and perhaps the country is not ready to take such a step.”);
Liivak, supra note 12, at 41 (emphasizing that his proposal does not require
statutory reform).
80
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II. THE INFORMATION-FORCING FUNCTION OF CLAIMS
A. An Analogy: The Value of Contracts of Adhesion
To begin, it is helpful to consider an analogous situation involving a
self-servingly drafted legal instrument. Consider a contract of adhesion
between a large corporation and a consumer. Because the written
contract is drafted solely by the corporation, it is likely to contain some
“fine print” that the consumer does not read and does not really
consent to. 84 In sum, there will be numerous subtle differences
between the real agreement or bargain—i.e. the actual meeting of the
minds of the parties—and the literal text of the written contract. For
clarity purposes, I will use the label “real bargain” to denote the former,
and the label “written contract” to denote the latter.
Every first year law student is confronted with the question of why
courts routinely enforce such contracts of adhesion as written, even
though consumers do not read them. 85 And the intuitive answer is that
courts should not pay any attention to such self-servingly drafted
contracts, and they should instead look for the real bargain. 86
But, once we really think about that alternative, it quickly emerges
that it is not feasible. If courts simply declared all form contracts
unenforceable and ignored such self-serving writings, the result is not
some utopia where formerly-powerless consumers now receive their
real bargain. 87 Rather, the likely result is a complete breakdown of the
contract system. In every case, the parties could dispute the terms of
their bargain, and they could dispute all the terms (e.g. the subjectmatter, the price, the timing, the quantity, etc.) because there would be
no written record to refer to. A court attempting to resolve the dispute
would essentially have to assemble the entire bargain from scratch,
and it would need to do so by sorting through a morass of self-serving
RICHARD A. POSNER, ECONOMIC ANALYSIS OF LAW § 4.9, at 116 (7th ed.
2007) (“form contracts . . . tend to be one-sided against the consumer”);
Jonathan Klick, The Microfoundations of Standard Form Contracts: Price
Discrimination vs. Behavioral Bias, 32 FLA. ST. U. L. REV. 555, 556 (2005) (“a
great many of the standardized terms appear to benefit the seller to the
potential detriment of the buyer”).
85 MARGARET JANE RADIN, BOILERPLATE: THE FINE PRINT, VANISHING
RIGHTS, AND THE RULE OF LAW 14 (2012) (stating that “incoming law
students . . . are astonished” to discover that adhesion contracts are binding).
86 See, e.g., id.; Todd D. Rakoff, Contracts of Adhesion: An Essay in
Reconstruction, 96 HARV. L. REV. 1173 (1983).
87 See RADIN, supra note 85, at 15 (acknowledging that “if all attempts to
use boilerplate were to be declared unenforceable, that would cause a
considerable disruption of current commercial practice”).
84
19
oral testimony and post-hoc litigation-driven evidence. 88 The chance
that a court could achieve anything resembling an accurate result—i.e.
one that actually matched the real bargain—is miniscule. In realistic
terms it would be utterly lost at sea.
In comparison to the chaos that would result, written contracts of
adhesion provide a reasonable approximation of the real bargain. The
drafting party knows what the real bargain is, and the written contract
discloses some of that information to the court. To be sure, the written
contract of adhesion will also be slanted to towards to drafter. But it
cannot be too greatly slanted: reputation, consumer experience, and
competitive pressures limit how far a company can go with the fine
print even when consumers do not read it. 89 Furthermore, the written
contract is memorialized at a time before the dispute arises, so the
drafting party is less likely to be able to disingenuously tailor the
slanting to fit the precise facts of the dispute, at least in comparison to
post-hoc oral testimony and litigation-driven evidence. From a
systemic viewpoint, enforcing written contracts of adhesion is better
than the alternative of courts essentially taking blind stabs in the dark
trying to recreate every bargain from scratch. Rather than detracting
from the real bargain, a written contract of adhesion is actually the
most reliable evidence of it. 90
Applying this analogy to patent claims is straightforward, 91 and my
argument in the remainder of this Part will elaborate on this analogy
in two steps. In Section B, I will argue that, like the real bargain,
courts cannot directly determine what the real invention is—they face
a severe information problem. In Section C, I will then explain how
patentee-written claims serve as a mechanism to partially overcome
this information problem.
See Trident Ctr. v. Conn. Gen. Life Ins. Co., 847 F.2d 564, 569 (9th Cir.
1988) (arguing that relaxing the plain meaning rule “creates much business
for lawyers and an occasional windfall to some clients [but] leads only to
frustration and delay for most litigants and clogs already overburdened
courts”).
89 POSNER, supra note 84, at § 4.9, at 116 (arguing that reputation and
competition cannot produce the optimal form contract but do limit abuse).
90 Slamow v. Del Col, 594 N.E.2d 918, 919 (N.Y. 1992).
91 Burk and Lemley make the same analogy, though they come to very
different conclusions. See Dan Burk & Mark A. Lemley, Quantum Patent
Mechanics, 9 LEWIS & CLARK L. REV. 29, 50 (2005) (arguing that a textualist
approach to claims is analogous to the “discredited” plain meaning approach
to contract interpretation). Given that the plain meaning approach is
followed to some extent by the overwhelming majority of jurisdictions, 2 E.
ALLEN FARNSWORTH, FARNSWORTH ON CONTRACTS § 7.12 at 294 (3d ed. 1999),
Burk and Lemley seem to have a rather odd definition of “discredited.”
88
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B. Courts Lack Information About the Real Invention
1.
The misconception of the invention as an embodiment.
In order to see why courts cannot easily determine what “the real
invention” is in a particular case, it is first necessary to rebut a very
common misconception. The misconception is that “the real invention”
for this purpose is the embodiment(s) described in the specification. 92
This misconception is intuitively appealing because the patent statute
explicitly says that the specification describes “the invention.” 93 And
even without this reference to the patent statute, many people
intuitively think that an invention is a gadget that has physical form,
i.e. an embodiment. 94
If we accept this conceptualization of the invention, then my entire
argument falls apart. The physical object that the patentee created is
easy for a court to discern—it can simply be wheeled into the
courtroom for all to see. Not only this, the patent specification will
provide a detailed description of the physical embodiment, including
all the details about how to make and use it. 95 There is no information
difficulty to be solved in such a regime and no policy function for
claims to serve.
But, as explained in Part I.A, patent law has never subscribed to
this conception, 96 because it leads to eviscerating the underlying
See, e.g., Netword, LLC v. Centraal Corp., 242 F.3d 1347, 1352 (Fed. Cir.
2001) (“The claims are directed to the invention that is described in the
specification; they do not have meaning removed from the context from which
they arose.”); Autogiro Co. v. United States, 384 F.2d 391, 397 (Ct. Cl. 1967)
(“An invention exists most importantly as a tangible structure.”); Liivak,
supra note 12, at 5 (conceptualizing the invention as “the set of embodiments
conceived and disclosed by the inventor in enough detail that they can be
reduced to practice”); Cotropia, supra note 64, at 1876 (conceptualizing the
invention as something that inventor “build[s]”).
93 35 U.S.C. § 112 (2006); see Howard T. Markey, Why Not the Statute?, 65
J. PAT. OFF SOC’Y 331, 333 (1983) (“Ideas are never patentable. Only
embodiments of an idea, i.e. an invention, may be patented.”).
94 See Giles S. Rich, The Relation Between Patent Practices and the AntiMonopoly Laws—Part II, 24 J. PAT. OFF. SOC’Y 159, 172 (1942) (stating that
an embodiment is “[p]opularly but inaccurately called ‘invention.’”).
95 35 U.S.C. § 112 ¶ 1. Patentees have the practical incentive to comply
with this statutory obligation, because the PTO can easily detect a situation
where the specification on-its-face fails to describe an embodiment. Cf. supra
text accompanying notes 42–46.
96 Pfaff v. Wells Elecs., Inc., 525 U.S. 55, 60 (1998) (“The primary meaning
of the word ‘invention’ in the Patent Act unquestionably refers to the
inventor’s conception rather than to a physical embodiment of that idea.”);
Smith v. Snow, 294 U.S. 1, 11 (1935) (“it is not necessary to . . . describe in
92
21
incentive goals of the patent system. 97 Consider again the Wright
brothers’ patent on the airplane. If we take seriously the
conceptualization of the invention as an embodiment, the logical
implication is that the monopoly they should receive—which of course
is defined by the “invention”—would cover only literal replication of a
wooden glider with cloth wings. This is the only type of airplane that
the Wright brothers actually described in the specification with
sufficient exactness and detail that another person in the aviation field
could build the same airplane. 98 The Wright brothers themselves could
not build (and thus could not have described how to build) even a
World War I fighter, 99 let alone a modern jet. Limiting the Wright
brothers’ monopoly to literal replication of a wooden glider with cloth
wings would render their patent worthless, thereby destroying the ex
ante incentive to invest in research and development. For this reason,
the specification embodiment is not the invention, at least not for the
purposes of defining patent scope.
Instead, the invention for patent scope purposes has always been
defined as the inventor’s idea. 100 The Wright brothers did not merely
invent a single wooden glider with cloth wings that flew for 59 seconds
at Kitty Hawk on December 17, 1903. They invented “the airplane,” 101
which is an idea that covers a large range of machines from a barelyflying wooden glider to a modern Boeing 747 jet. It is a fundamental
the specifications all possible forms in which the claimed principle may be
reduced to practice”).
97 Graver Tank & Mfg. Co. v. Linde Air Prods. Co., 339 U.S. 605, 607
(1950).
98 SRI Int’l v. Matsushita Elec. Corp., 775 F.2d 1107, 1121 (Fed. Cir. 1985)
(en banc) (“The law does not require the impossible. Hence, it does not
require that an applicant describe in his specification every conceivable and
possible future embodiment of his invention.”).
99 See G.D. Padfield & B. Lawrence, The Birth of Flight Control: An
Engineering Analysis of the Wright Brothers’ 1902 Glider, 107 AERONAUTICAL
J. 697, 717 (2003) (stating that “after 1908 the rate of progress in aviation
was quite startling; progress which, in many ways, would leave the Wright
brothers behind”).
100 See, e.g., Pfaff, 525 U.S. at 60; Cont’l Paper Bag Co. v. E. Paper Bag Co.,
210 U.S. 405, 418–19 (1908) (“The principle of the invention is a unit, and
invariably the modes of its embodiment in a concrete invention may be
numerous and in appearance very different from each other.”); Winans v.
Denmead, 56 U.S. (15 How.) 330, 343 (1853) (“[I]t is the duty of courts and
juries to look through the form for the substance of the invention—for that
which . . . the patent was designed to secure .”).
101 WENDIE C. OLD, THE WRIGHT BROTHERS: INVENTORS OF THE AIRPLANE
(2000).
22
mistake—albeit a common one—to conflate the embodiment with the
inventive idea. 102
2.
The problem of identifying the inventive idea.
Once we understand that the “invention” is not an embodiment but
an idea, a problem quickly arises: An idea can be characterized at
multiple levels of abstraction, all of which are equally accurate as a
matter of logic. 103 For example, consider again the Wright brothers’
invention of the airplane. Is the inventive idea:
a) Artificial powered flight?
b) Artificial powered flight using wings and a rudder?
c) Artificial powered flight using cloth wings and a wooden rudder?
Each of these levels of abstraction is a plausible description of the
Wright brothers’ inventive idea. But they have very different
implications for the real world. A monopoly that covers all powered
flight would cover, for example, later developed helicopters and a
future antigravity spaceship. This would provide very strong incentives
for the Wright brothers and other similarly-situated inventors to make
investments in research, but it would also impose very high monopoly
costs. A monopoly that covered only powered flight using wings and
rudders would not cover helicopters, but would still cover all later jet
airplanes including those made with aluminum and modern composite
materials. This represents an intermediate level of both incentives and
monopoly costs. Finally, a monopoly that covered only airplanes using
cloth wings and wooden rudders would cover essentially nothing,
which produces no monopoly costs but also no incentives.
How should the patent system choose among these competing
alternatives? Almost everyone at some level agrees that the choice
should be based on the economic consequences. 104 That is, the patent
system should aim to award patentees the idea at the level of
abstraction that optimally balances the incentive benefits and the
monopoly costs. For example, Burk and Lemley say that courts should
look for the “ideal scope of the patent.” 105 Cotropia echoes this by
STRINGHAM, supra note 30, at 209; MERGES & DUFFY, supra note 75, at
27 (“It is very important in patent law not to confuse the invention claimed in
the patent with the physical manifestations or ‘embodiments’ of the invention.
For purposes of patent law, the invention is only the concept or
principle . . . .”).
103 Tun-Jen Chiang, The Levels of Abstraction Problem in Patent Law, 105
NW. U. L. REV. 1097 (2011) (describing this problem).
104 Id. at 1139; see generally Robert P. Merges & Richard R. Nelson, On the
Complex Economics of Patent Scope, 90 COLUM. L. REV. 839 (1990).
105 Burk & Lemley, supra note 2, at 1762.
102
23
arguing that that the invention should be defined by “basic patent
theory,” 106 which in standard parlance means the economic balance
between incentives and monopoly costs. 107 And Lee explicitly
recognizes that his proposal ultimately calls for courts to “calibrat[e]
patent scope to maintain incentives to invent without unduly
burdening sequential developments.” 108
Saying that the real invention is conceptually a matter of finding
economically optimal patent scope is not to say that courts must
necessarily phrase the doctrinal test in such an explicit manner. For
example, they can instead say that the invention is the patentee’s
embodiment plus all substantially similar embodiments—this is the
doctrinal test that Burk and Lemley seem to propose. 109 But such a
doctrinal test will only raise the question of what “substantial
similarity” means—what counts as “substantial” and as “similar”? A
legal construct such as a substantial similarity test must ultimately
have an underlying theory, or it will be an incoherent jumbled mess. 110
It is hard to see what that underlying theory would be except to
achieve optimal economic balancing of incentive benefits and monopoly
costs (who wants to defend a non-optimal theory?); 111 and the critics
themselves seem to envision the substantial similarity test as
operating as a proxy for this economic question. 112
Cotropia, supra note 64, at 1913.
Merges & Nelson, supra note 104, at 868 (“The analysis has
concentrated on how changing patent coverage affects the balance between
incentives to the inventor and underuse of the invention due to patent
monopolies.”).
108 Lee, supra note 12, at 111.
109 Burk & Lemley, supra note 2, at 1768 & 1785 (arguing for a return to
nineteenth century doctrine, which used a substantial similarity test); see
also Cotropia, supra note 64, at 1910–13 (arguing for greater reliance on the
doctrine of equivalents, which uses a substantial similarity test).
110 The best analogy is “reasonableness” in tort law. The Hand formula of
B<PL is useful precisely because it provides an underlying theory for what
reasonableness means. See RICHARD A. POSNER, TORT LAW: CASES AND
ECONOMIC ANALYSIS 1–9 (“This casebook is premised on the belief that the
Hand formula . . . provides a unifying perspective in which to view all of tort
law.”). Without an underlying theory, a doctrinal test becomes a matter of “I
know it when I see it”—an incoherent mess. Cf. Jacobellis v. Ohio 378 U.S.
184, 197 (1964) (Stewart, J., concurring) (describing the obscenity doctrine in
this way).
111 See Michael J. Meurer & Craig Allen Nard, Invention, Refinement and
Patent Claim Scope: A New Perspective on the Doctrine of Equivalents, 93
GEO. L.J. 1947, 1967–68 (2005) (arguing that the doctrine of equivalents is
based on an economic efficiency theory).
112 See supra text accompanying notes 105–109.
106
107
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3.
The impossibility of direct determination.
Once we recognize that the real invention is not an embodiment, but
an idea at a level of abstraction that represents optimal patent scope,
the fundamental information difficulty of the patent system becomes
apparent: Courts do not have the information to calculate optimal
patent scope, or even to approximate it in any meaningful way. This is
self-evidently true both as a theoretical and an empirical matter.
As a theoretical matter, the entire reason for having a patent system
at all is that the government (including a court) does not have enough
information to directly determine the social costs and benefits of a
particular patent. 113 If such a direct calculation could be done, then it
would be more efficient to have judges award taxpayer-funded prizes
than to award patent monopolies. 114 And this would still be true even
if judges could only make approximate guesses about the benefits and
costs—roughly-optimal prizes are still more efficient than roughlyoptimal monopolies. The central theoretical premise of having a patent
system is that judges cannot meaningfully do case-by-case economic
balancing. If this is not true, then the solution is not to abolish claims,
but to abolish the entire patent system.
As an empirical matter, economists have made repeated attempts to
study the social costs and benefits of the patent system, all with
inconclusive results. 115 The same information problems—the intrinsic
difficulty of measuring social costs and benefits—will plague any
attempt to conduct similar studies as to individual patents. It is
fanciful to believe that judges or juries—even aided by expert
Kaplow, supra note 8, at 1844.
Id.; Michael Kremer, Patent Buyouts: A Mechanism for Encouraging
Innovation, 113 Q.J. ECON. 1137, 1140 (1998) (“financing research with
monopoly profits . . . is generically less efficient than financing research with
tax revenue”); see generally Daniel Jacob Hemel & Lisa Larrimore Ouellette,
Beyond the Patent-Prizes Debate, 92 TEX. L. REV. (forthcoming 2014)
(discussing non-patent mechanisms for funding research).
115 George Priest, What Economists Can Tell Lawyers About Intellectual
Property, 8 RES. L. & ECON. 19, 21 (1986) (“economists know almost nothing
about the effect on social welfare of the patent system”); Fritz Machlup, An
Economic Review of the Patent System, Study No. 15, Subcommittee on
Patents, Trademarks, and Copyrights of the Senate Committee on the
Judiciary, 85th Cong., 2d Sess. 79–80 (1958) (“No economist, on the basis of
present knowledge, could possibly state with certainty that the patent system,
as it now operates, confers a net benefit or a net loss upon society.”).
113
114
25
witnesses—can determine anything remotely resembling the optimal
scope of a patent in an individual patent case. 116
No critic of patent claims has proposed an alternative methodology
for determining patent scope that addresses this information difficulty.
The most common proposed methodology by far is that courts should
look to the patent specification instead of the claim. 117 But this comes
back to the point made in Part II.B.1. If the “invention” being
discussed were an embodiment, then looking primarily to the
specification would make a lot of sense. 118 But once we acknowledge
that the “invention” does not refer to a concrete embodiment and
instead refers to an economic balancing act, then the specification
provides almost no information for the inquiry.
In contrast to the specification, Peter Lee and Craig Allen Nard
argue that courts should look primarily to the testimony of expert
witnesses and other industry participants to determine patent
scope. 119 This is a more plausible suggestion—experts and other
industry participants might know something about the economic
benefits and costs of the patent. But unless either Lee or Nard is
suggesting that courts should hold patent trials running for months
and years, and to summon a veritable army of both economics experts
and industry participants, the amount of information that can be
collected on the question will still be tiny relative to the amount
required to actually reach meaningful conclusions. 120 The problem is
not only that paid experts in litigation have little incentive to testify
honestly 121 —though that too is a problem—the bigger problem is that
See Frank H. Easterbrook, The Limits of Antitrust, 63 TEX. L. REV. 1, 11
(1984) (discussing the difficulty of judicially discerning economic efficiency).
117 Cotropia, supra note 64, at 1909–10; Liivak, supra note 12, at 44; see
also Retractable Techs., Inc. v. Becton, Dickinson & Co., 653 F.3d 1296, 1311
(Fed. Cir. 2011) (Plager, J., concurring) (“[T]he claims cannot go beyond the
actual invention that entitles the inventor to a patent. For that we look to the
written description.”).
118
See Christopher A. Cotropia, Patent Claim Interpretation and
Information Costs, 9 LEWIS & CLARK L. REV. 57, 68–72 (2005) (arguing that
the specification produces information about the invention).
119 Lee, supra note 12, at 104; Craig Allen Nard, A Theory of Claim
Interpretation, 14 HARV. J.L. & TECH. 1, 57–63 (2000).
120 See Easterbrook, supra note 116, at 11 (“If we assembled twelve
economists and gave them all the available data about a business practice,
plus an unlimited computer budget, we would not get agreement about
whether the practice promoted consumers’ welfare or economic efficiency
more broadly defined.”).
121 Cf. Nard, supra note 119, at 63 (focusing on the honesty problem).
116
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the experts simply would not be able to calculate the optimal patent
scope even if they were (miraculously) motivated to testify honestly. 122
Finally, there is one method by which judges and juries could make
direct assessments of optimal patent scope despite the information
difficulty, and at very low adjudication cost: They can simply make
uninformed stabs in the dark on the question. 123 At the end of the day,
this is what the critics’ proposed regime would amount to—they would
throw the question to the jury and have it worked out in the black box,
under some open-ended test such as “substantial similarity.” 124 A court
could mask the emptiness of its decision by conducting a long trial,
reading the specification ten times, collecting a library’s worth of prior
art, and calling a great number of impressively credentialed expert
witnesses; but the ultimate decision would still be empty and
uninformed. As the Supreme Court once observed about patent
adjudication in the era before claims were invented, it entailed
“laborious” effort by courts while producing results that were no better
than “inference and conjecture.” 125 This was because of the intrinsic
lack of information.
C. Claims Force Information from Patentees
If attempting a direct calculation of optimal patent scope cannot
yield good results, then how should the patent system make informed
decisions about patent scope? As part of answering that question,
consider the fact that, of all the people in the world, the patentee has
the best information on the optimal scope of the patent. 126 As a matter
of first principles, the optimal scope of the patent is the lowest amount
of monopoly that would induce an inventor to create and disclose the
technology described in the specification. 127 The patentee obviously
Priest, supra note 115, at 21; Easterbrook, supra note 116, at 11.
Cf. Frank H. Easterbrook, On Identifying Exclusionary Conduct, 61
NOTRE DAME L. REV. 972, 980 (1986) (“What we need is a set of intelligent
presumptions, not a stab at the ultimate question of efficiency.”).
124 See Burk & Lemley, supra note 2, at 1768 & 1785 (arguing for
substantial similarity test); Cotropia, supra note 64, at 1910–12 (same).
125 Keystone Bridge Co. v. Phoenix Iron Co., 95 U.S. 274, 278 (1877).
126 Long, supra note 9, at 496-97 (“In almost all cases, owners will know
more about their intellectual goods than observers will.”).
127 See Graham v. John Deere Co., 383 U.S. 1, 11 (1966) (framing the
question as whether the invention would “be disclosed or devised but for the
inducement of a patent”).
122
123
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knows what the minimum amount of monopoly reward that he needs
is. 128
The difficulty here is that patentees have no incentive to honestly
disclose their superior information. What patent law needs is, in
economic parlance, an information-forcing mechanism. 129
Patent claims serve as this information-forcing mechanism. A
patentee who writes a claim down takes a public position that he
believes this particular claim to represent the optimal degree of patent
scope for his particular contribution. The very fact that the patentee
must take a definitive position on the issue forces the patentee to
reveal some of his private information. A patentee will not fully
disclose his true belief of optimal patent scope, but at the same time he
will disclose a reasonable approximation of it.
That last sentence requires some explanation, because the intuitive
counterargument is that a patentee would have no incentive to be
reasonable and disclose an approximation of his true beliefs. If
patentees had an information advantage, it would seem at first blush
that they should ruthlessly exploit it and claim as much as possible. If
patentees really had more information than courts, why don’t they just
claim “everything under the sun” and then rely on the fact that courts
do not have enough information to determine if that degree of patent
scope is correct or not? What forces patentees to disclose—or at least to
partially disclose and thus approximate—their true beliefs about
optimal scope?
The answer is that patentees are constrained by an intrinsic
asymmetry between the effort required to take an affirmative position,
and the effort required to react to a position that someone else has
taken. Stated another way, it is easier—less information intensive—for
a decision-maker to determine that a position is incorrect than it is for
the same decision-maker to affirmatively state what the correct answer
is.
See Kintner v. Atl. Communication Co., 240 F. 716, 717 (2d Cir. 1917)
(“the patentee is conclusively presumed to have known what he invented or
discovered, better than did any one else, at the time he applied for a patent”).
129 This fits within a more general economics literature on how decisionmakers can elicit useful information from better-informed but self-interested
parties. See Chris W. Sanchirico, Relying on the Information of Interested—
and Potentially Dishonest—Parties, 3 AM. L. & ECON. REV. 320 (2001); Ian
Ayres & Robert Gertner, Filling Gaps in Incomplete Contracts: An Economic
Theory of Default Rules, 99 YALE L.J. 87, 97–100 (1989); Paul Milgrom &
John Roberts, Relying on the Information of Interested Parties, 17 RAND J.
ECON. 18, 19–20 (1986).
128
28
To see this point, consider the following assertion: “The economically
optimal speed limit on interstate highways is 55 miles per hour.”
Virtually everyone will be able to say with a good amount of confidence
that this is false. The sentence misstates what the economically
optimal speed limit on interstate highways is. In locations where a 55
mph speed limit is in force, nobody obeys it; and if people did, traffic
would come to a standstill, causing commerce to slow and the economy
to suffer. In short, we can easily determine that the statement is not
correct.
Now I ask you to state what the economically optimal speed limit on
interstate highways is. In all likelihood, you would have no idea where
to start. Is it 65? 70? 80? We simply do not have adequate information
to answer the question, and any answer we gave would be nothing
more than a rough guess. In sum, it is easier to know that a position
someone else has taken is incorrect, than it is to affirmatively take the
correct position yourself.
Applied to the context of patent claims, a patentee who writes a
claim takes a position that a court can then evaluate and scrutinize. It
is true that, in the absence of any enforceable constraint, a rational
patentee would blatantly lie and assert a monopoly that covers
absolutely everything. But the patentee is constrained—he cannot
claim too much or a court (or the PTO) will strike the claim down as
invalid. 130 The key here is that it is easier for a court or the PTO to
determine whether a claim is wrong—i.e. whether the claim is overbroad and would result in excessive monopoly scope if upheld—than
for a court or the PTO to affirmatively state in the first instance what
the right degree of monopoly scope is. Thus, courts and the PTO only
evaluate patentee-drafted claims, and they do not affirmatively state
the approvable degree of patent scope in the first instance. 131 Even
after the PTO rejects a patentee-drafted claim, the usual procedure is
to send it back to the patentee for redrafting: the PTO merely says the
patentee is wrong; it does not say what would be right.
Once we understand the information-forcing function of claims, the
practice of relying on patentee-drafted claims is revealed to be an
Courts have a variety of doctrines they can invoke to invalidate claims
that create excessive monopoly cost. See Merges & Nelson, supra note 104, at
841 (explaining the doctrinal mechanisms that courts have to control patent
scope); Tun-Jen Chiang, Defining Patent Scope by the Novelty of the Idea, 89
WASH. U. L. REV. 1211, 1227–32 (2012) (same).
131 It is for this reason that the patent system also disallows so-called
“omnibus claims.” Ex parte Fressola, 27 U.S.P.Q.2d 1608, 1612 (Bd. Pat. App.
& Inter. 1993). An omnibus claim is a claim that says something like “I claim
whatever the law allows.” Such an empty claim discloses no information.
130
29
efficient solution to the patentee’s information advantage, and to
thereby reduce judicial information costs. 132
The information forcing function of claims explains not only why the
patent system forces patentees to write claims. It also explains why the
patent system requires claims to be written early in the life of a patent,
at the time of initial patent filing. One might not initially think this is
a good idea—Burk and Lemley are specifically critical of this feature of
claiming practice. 133 According to Burk and Lemley, more information
about the social benefits and costs of a patent become available once
people actually start making and selling widgets in the market. 134
Therefore, the patent system should wait before memorializing the
scope of the patent in a claim. 135
But a patentee’s private information does not increase over time. At
the time of patent filing, the patentee already has all the information
he ever needs to know about the optimal scope of the patent: how much
incentive he needed to create and disclose the technology that is being
patented. 136 And compelling the patentee to disclose this information
early has value because it ensures that the patentee is more likely to
be honest in the disclosure. 137 After a competitor enters the market
with a new product, a patentee will have an obvious incentive to
retroactively pretend that the competitor’s product was part of his
invention at the time he filed the patent, even if this is not true. 138 He
will be able to tailor his litigation position to match the exact facts of
the competitor product. By requiring the patentee to file claims at the
time of filing, the patent system creates a record of the patentee’s
position before such tailoring can occur. 139
At least one critic has previously recognized this function of claims. See
Cotropia, supra note 118, at 72–74 (describing claims as an “information
producing” mechanism). Yet Cotropia now seems to attach little value to
claims, preferring instead to rely primarily on the specification to dictate
patent scope. Cotropia, supra note 64, at 1909.
133 Burk & Lemley, supra note 2, at 1782.
134 Id.
135 Id.
136 See supra text accompanying note 127.
137 Tun-Jen Chiang, Fixing Patent Boundaries, 108 MICH. L. REV. 523, 543
(2010).
138 Id.; Robert P. Merges, Software and Patent Scope: A Report from the
Middle Innings, 85 TEX. L. REV. 1627, 1653 (2007) (calling this
“misappropriation by amendment”); Mark A. Lemley & Kimberly A. Moore,
Ending Abuse of Patent Continuations, 84 B.U. L. REV. 63, 111 (2004).
139 A wrinkle here is that the patent system also allows patentees to
amend their claims and tailor the amended claim to cover new products. This
dilutes the information benefit of early-filed claims and is a practice that I
132
30
The result is that, contrary to Burk and Lemley, the patent system
in fact adopts the correct timing of decision-making to account for
information costs. It requires the patentee to write the claim at an
early time (when the patentee already has all the relevant private
information, and also is more likely to be honest), but it has courts
making the final decision at the later time of infringement litigation,
where the accusation is necessarily that the defendant is participating
in a market that makes and sells a widget that embodies the
invention. 140 This timing two-step allows courts to have the most
information possible about the correct scope of the patent when
making their adjudication decision: a court will have both the
patentee’s early written claim and the later market evidence. This is
the best state of information that courts can reasonably obtain, though
of course it is far from perfect.
D. The Imperfection of Claims and Ex Post Adjustment
One important corollary to information-forcing function of claims,
implicitly stated in the previous Section, is that courts need to engage
in what I will call “ex post adjustment.” That is, when a patentee has
blatantly over-claimed, courts must be able to rectify this, or else there
would be no constraint on even the most egregious over-claiming. The
claim is therefore not the final word on patent scope: a court’s decision
is the final word on patent scope. The claim merely supplies
information for that decision. The fact that courts make the ultimate
decision on patent scope and claims are a tool for this purpose, rather
than the master-servant relationship running the other way (i.e. as
opposed to saying that claims dictate patent scope and courts merely
have the ministerial task of robotically administering the text), leads
to several implications.
First, ex post adjustment calls for consideration of external evidence.
In order for courts (and the PTO) to engage in ex post adjustment, they
must be able to determine that the claim text is overbroad. And a court
must obviously refer to something other than the claim text itself to
make that determination, i.e. it must refer to external evidence. Thus,
my theory does not exclude external evidence from the claim
construction calculus. I am not calling for judges to be strict textualists
who mechanically apply claim text in every case.
and many others have criticized. Chiang, supra note 137, at 543; Merges,
supra note 138, at 1653; Lemley & Moore, supra note 138, at 111. But, at the
very least, an early written claim preserves the original record and allows us
to detect a later change in position by the patentee. If claims were abolished,
then there would be no record of the patentee’s original position at all.
140 See 35 U.S.C. § 271(a) (2006) (defining infringement as making, using,
selling, or importing [an embodiment of] the invention).
31
Second, notwithstanding the fact that my theory calls for ex post
adjustment and calls for external evidence, the key point of my theory
is that it uses claim text as a baseline. The role of external evidence
under my theory is only to supplement the claim and to adjust patent
scope relative to the baseline that the patentee first sets through the
claim. This makes it very different from the critics’ theory. In the
critics’ telling, the claim is a valueless—indeed affirmatively harmful—
self-serving statement that deserves no role because it detracts from
the real invention. 141 The critics rely on external evidence to provide
the substantive baseline to determine patent scope. Although they are
mostly content to leave claims in place as undead zombies to avoid the
hassle of statutory amendment, 142 the critics are ultimately arguing
for external evidence to replace claim text in everything but name.
Claim text has an important conceptual and practical role in my theory
that they lack under the critics’ theory.
Third, the court can engage in ex post adjustment using a variety of
doctrinal tools. At a high level, a court has at least two options in
dealing with an overbroad claim: (a) it can creatively construe the
claim narrowly, or (b) it can invalidate the claim. 143 The practical effect
of each option is similar: under either option, the patentee ends up
with a monopoly scope that is narrower than what the claim text itself
would indicate. 144 And the result of this ex post adjustment is to
Burk & Lemley, supra note 2, at 1746 (“If patent-claim terms lack the
virtue of certainty and are in fact doing mischief in the patent system,
perhaps we should begin to rethink the whole enterprise.”).
142 See Liivak, supra note 12, at 41 (“strongly” agreeing with Burk and
Lemley’s theoretical position, but arguing that it does not require “any
significant statutory reform” to implement). Even Burk and Lemley, who do
advocate for the statutory abolition of claims, express the reservation that
“perhaps the country is not ready to take such a step” because of inertia.
Burk & Lemley, supra note 2, at 1747.
143 See Roger Allan Ford, Patent Invalidity Versus Noninfringement, 99
CORNELL L. REV. (forthcoming 2013) (noting invalidity and non-infringement
are functional substitutes); Roger Shang & Yar Chaikovsky, Inter Partes
Reexamination of Patents: An Empirical Evaluation, 15 TEX. INTELL. PROP.
L.J. 1, 25 (2006) (“In almost every patent litigation, the defendant must
choose between two competing strategies: arguing for a narrow claim
interpretation to avoid infringement, or arguing for a broad claim
interpretation to invalidate the patent.”).
144 Another option is to find infringement but then award no (or fewer)
remedies. See EBay Inc. v. MercExchange, L.L.C., 547 U.S. 388, 397 (2006)
(Kennedy, J., concurring) (suggesting that courts may be more inclined to
deny injunctions for overbroad business method patents). This reduces the
patentee’s monopoly rent and thus achieves a similar effect at an economic
level.
141
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mitigate the patentee’s drafting bias and bring the actual monopoly
reward awarded closer to the ideal scope of the patent.
The corollary to this third point is the question: So which option
should a court use? The answer is that it depends on the circumstances
of the individual case, because the options have different pros and cons.
Creatively narrowing a claim rather than striking the claim down has
the obvious benefit of avoiding an extreme result that clearly underincentivizes the patentee (giving zero scope), and it has a political
benefit to a court in terms of avoiding an overt disagreement with
another branch of government (invalidating a claim that the PTO had
previously allowed). 145 But it has the cost of forcing the court to take
an affirmative position on the correct scope of the patent, which is
more information intensive. 146 Conversely, invalidating a claim
reduces the information cost, but it creates an extreme zero-scope
outcome and also a political cost. Courts must weigh the pros and cons
of each route in the individual case, and unsurprisingly the result is
that courts do not consistently take one approach or the other. 147 On
the other hand, the PTO faces no such tradeoff, because it creates no
conflict with another branch of government in rejecting a claim, and a
rejected claim does not result in zero scope because a patentee can
submit an amended claim in response to a rejection. 148 Therefore, the
PTO only rejects claims; it is not able to creatively narrow them. 149
Fourth, once we accept that claims are merely a tool and courts
make the final decision on patent scope, the key practical question is
how courts should make that decision, and in particular the role of
claims in the calculus. Should courts give claims a great deal of weight,
or very little? The next Part deals with this question.
III. IMPLICATIONS FOR THE CLAIM CONSTRUCTION DEBATE
As an initial matter, the analysis in Part II obviously refutes one
extreme position as to the role of claims in a court’s determination of
See 35 U.S.C. § 282 (2006) (stating that claims issued by the PTO are
entitled to a presumption of validity).
146 See supra Part II.C.
147 Compare Turrill v. Michigan Southern & N.I.R. Co., 68 U.S. 491, 510
(1863) (holding that claims should be construed narrowly if necessary to save
their validity) with Rhine v. Casio, Inc., 183 F.3d 1342, 1345 (Fed. Cir. 1999).
(“[I]f the only claim construction that is consistent with the claim's language
and the written description renders the claim invalid, then . . . the claim is
simply invalid.”).
148 37 C.F.R. § 1.111(a) (2012) (permitting amendments in response to a
rejection).
149 See SRAM Corp. v. AD-II Eng’g, Inc., 465 F.3d 1351, 1359 (Fed. Cir.
2006) (PTO interpretation of claims has no legal effect).
145
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patent scope, which is to abolish or ignore claims altogether. Without
claims, courts would have to attempt a direct assessment of optimal
patent scope from scratch. Both as a matter of theoretical deduction
and of empirically-established reality, it is clear that courts cannot
perform this direct inquiry, even as an approximation. 150 Thus, it
would be unwise to abolish or ignore claims entirely.
A reader may respond with a less extreme theory: Courts should not
abolish or disregard claims, but they should also consider the full
range of external evidence—and give external evidence more weight
than claim text—in order to compensate for the patentee’s drafting
bias. 151 As I shall explain, even this approach has an important and
overlooked limit.
It is helpful to consider again the analogy to contract law. In
contract law, no one contends that courts should abolish or ignore
written contracts altogether. Nor is there any argument that courts
should give extrinsic evidence more weight than the contract text. But
there is a long-running debate about whether extrinsic evidence should
be given less weight—and, if so, how much less weight—than the
written contract. There are two stylized extreme positions that have
both been well articulated: Arthur Corbin is famously associated with
the position that courts should consider all the evidence equally when
interpreting a contract, without disfavoring extrinsic evidence. 152 At
the other extreme, the strongest form of the plain meaning rule says
that courts should consider only the written contract itself and exclude
extrinsic evidence completely. 153 As Eric Posner has observed, real life
courts take intermediate positions on the spectrum between these two
See supra Part II.B.3.
See, e.g., Lee, supra note 12, at 106 (arguing that “extrinsic evidence . . .
provides a more accurate description of the technological scope of a patented
invention”); Burk & Lemley, supra note 2, at 1785 (outlining an alternative to
abolition that retains claims “as part of the overall description of the
invention as actually conceived and executed by the inventor”).
152 Arthur L. Corbin, The Interpretation of Words and the Parol Evidence
Rule, 50 CORNELL L.Q. 161, 188–89 (1965) (arguing that “no relevant
evidence [should be] inadmissible simply because it is extrinsic”); Arthur L.
Corbin, The Parol Evidence Rule, 53 YALE L.J. 603, 622 (1944) (“No parol
evidence that is offered can be said to vary or contradict a writing until by
process of interpretation the meaning of the writing is determined.”).
153 5 JOSEPH M. PERILLO, CORBIN ON CONTRACTS § 24.7, at 33 (rev. ed.
1998) (hereinafter “Corbin on Contracts”) (describing the plain meaning rule).
150
151
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extremes. 154 At the same time, as even Corbin concedes, they tend to
be closer to the pole of plain meaning. 155
The critics of patent claims are making essentially the same
argument as Professor Corbin, though they often go even further by
arguing courts should give external evidence more weight than claim
text. In Section A, I will explain that the Corbin methodology does
contain one important insight: In any given individual case,
considering all the available evidence equally will produce the most
accurate outcome.
However, in Section B, I will describe an important and oftenoverlooked limit to the Corbin approach. In the long run, the patent
system needs to provide some incentive for patentees to write claims.
As a practical matter, courts can only provide this incentive by giving
patentee-drafted claim text more interpretative weight than other
sources of evidence. As Eric Posner has explained in the contract law
setting, taking the Corbin approach to its extreme in every case leads
to the long-run consequence of having no written contracts. 156 The
same problem is true for patent law.
This does not mean that courts should therefore go to the opposite
extreme of robotically following the text in every case, either in
contract law or in patent law. Rather, as Section C discusses, courts
should balance the competing considerations of short-run accuracy and
long-run incentives. The result is that courts should not completely
exclude external evidence, but they should give claim text more
interpretative weight. As Part IV.A will later discuss, this is basically
descriptive of what patent courts do right now. It is also largely
descriptive of what contract courts do. 157 My theory thus provides both
a normative and descriptive theory for claim construction.
A. Short-run Efficiency: Equal Weight to All Evidence
If we take my point in Part II as a given—that is, if we assume for
present purposes that claims provide valuable but imperfect
information about the invention—then what should a court do with
them as a policy matter? A common intuition is to say that the job of a
Posner, supra note 16, at 538–40.
5 CORBIN ON CONTRACTS § 24.7 at 34 (“the ‘plain meaning rule’ is
adhered to by a majority of the jurisdictions in the United States”);
FARNSWORTH, supra note 91, at § 7.12, at 294 (“A few other courts have
shown sympathy for Corbin’s view, but the overwhelming majority of courts
retains some kind of plain meaning rule.”).
156 Posner, supra note 16, at 544.
157 See supra text accompanying notes 154–155.
154
155
35
court is to get the most accurate outcome possible. 158 That is, a court
should try and get to the real invention and to optimal patent scope. 159
Of course, even in an individual case, a court is constrained in its
pursuit of accuracy by finite adjudication resources. Courts cannot
realistically hold years-long trials, nor can they summon thousands of
experts. Thus, our initial focus on accuracy must be qualified: courts
should attempt to get the most accurate outcome at a given level of
adjudication resources. But, beyond resource constraints, the intuition
is that there should be no artificial limits imposed. Within this
paradigm, a court should aim to allocate its budget to maximizing the
pursuit of truth: the court should collect as much evidence as feasible,
and then consider all the evidence it collects on an equal basis.
By “equal” weight, I do not mean that the court would say, “witness
A, the upstanding citizen, says the defendant stabbed the victim, while
witness B, the known habitual liar, says the defendant did not, and
because all evidence is given equal weight the result is a toss-up.” I
mean that a court will consider all the evidence in light of its
credibility and in the totality of the circumstances, to get to the result
that is most likely to be reflective of the underlying factual truth on
the question at issue. The contradistinction is to a regime where courts
are required by a pre-set rule to favor or disfavor certain types of
evidence. For example, a court that excludes a bloody knife that was
obtained through an illegal search thereby gives this evidence zero
weight. The court does so not because it thinks the knife is unreliable
evidence, or that the underlying factual truth is that the defendant is
innocent, but because the pre-set exclusionary rule mandates that
evidence obtained though illegal searches be given zero weight. 160
By definition, therefore, a court that is seeking to maximize
accuracy in the individual case would consider all the available
evidence equally. But this formulation is not just a rhetorical trick.
The substantive point is that, if the goal is simply to maximize
accuracy, the law should rarely have categorical rules that exclude or
Kenworthey Bilz, We Don’t Want to Hear It: Psychology, Literature, and
the Narrative Model of Judging, 2010 U. ILL. L. REV. 429, 442 (observing that
the notion that courts should sacrifice accuracy for some other social purpose
“causes rebellion in the hearts of . . . many lawyers, policy makers, and
academics”).
159 See, e.g., Burk & Lemley, supra note 2, at 1762 (arguing that courts
should look for the ideal scope of the patent); Lee, supra note 12, at 104
(arguing that courts should “optimiz[e] patent scope”).
160 Mapp v. Ohio, 367 U.S. 643, 655 (1961).
158
36
disfavor broad swaths of evidence. 161 It should instead use a totality-ofthe-circumstances inquiry that considers both the claim text and all
reasonably collectible extrinsic evidence. And such totality-of-thecircumstances inquiries are what Corbin and his fellow travelers in
patent law propose. 162
B. Long-run Incentives: More Weight to Claim Text
It is a familiar proposition that the legal system will frequently
sacrifice accuracy in an individual case for other social policy goals. 163
The idea often causes discomfort among lawyers, judges, and
academics, 164 but it a pervasive part of the legal system. I have already
given the example of the exclusionary rule in the Fourth Amendment
context, which excludes evidence for long-run policy purposes (to deter
future constitutional violations) that are not related to maximizing
accuracy in the individual case. 165 Similarly, evidentiary privileges
such as the attorney-client privilege exclude a suspect’s confession to
his lawyer not because such a confession is unreliable, but because
without the privilege there would be no confession in the first place,
and there would be a social cost in terms of hindering effective
communication between lawyers and their clients.166 More generally,
the entire patent system is about this kind of tradeoff between shortrun welfare and long-run incentives. 167
The same essential dynamic plays out in the case of the role of
external evidence in determining patent scope. As above, the short run
optimal result in a given case—where the patent claim has already
See Davis v. United States, 131 S. Ct. 2419, 2423 (2011) (narrowing the
exclusionary rule because it detracts from maximizing truth).
162 See Nard, supra note 119, at 60 (citing Corbin and arguing that all
evidence should be considered in claim construction); Burk & Lemley, supra
note 2, at 1778–79 (analogizing this to the rules versus standards debate);
Lee, supra note 12, at 105 (arguing for a “holistic” approach that allows more
“context”); Cotropia, supra note 64, at 1913 (arguing for a “case-by-case”
approach that “contextualizes” the inquiry).
163
GLEN WEISSENBERGER & JAMES J. DUANE, FEDERAL RULES OF
EVIDENCE: RULES, LEGISLATIVE HISTORY, COMMENTARY AND AUTHORITY
§ 501.3, at 200 (2001) (noting that most evidentiary privileges have this
character).
164 Bilz, supra note 158, at 442.
165 Davis, 131 S. Ct. at 2426–27.
166 See Upjohn Co. v. United States, 449 U.S. 383, 395 (1981) (arguing that
the adversary is “in no worse position than if the communications had never
taken place”).
167 Michael Abramowicz, The Uneasy Case for Patent Races over Auctions,
60 STAN. L. REV. 803, 809-10 (2007) (“This trade-off between static and
dynamic efficiency is familiar to patent scholarship.”).
161
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been drafted—is to give everything equal interpretive weight. Such a
methodology maximizes the information available to a court and gets
us closest to optimal patent scope. But such a regime has a long run
cost: If courts simply took the patentee’s claim for what it was worth in
the totality of the circumstances, and gave it no particular weight, then
patentees would have no incentive to spend money hiring attorneys to
draft claims. 168 The long-term result would be the de facto abolition of
patent claims, which would then increase judicial information costs for
all the reasons that I have already described.
One objection that should be addressed at this point is that my
argument (that giving claims no weight would result in de facto
abolition) is belied by the historical record. As a historical matter,
claims were first developed by patentees in the nineteenth century,
before formal doctrine gave claims any weight in patent scope
determinations. 169 The fact that at least some patentees had sufficient
incentives to draft claims even in an environment where doctrine gave
claims no weight seems to strongly contradict my thesis.
But, in determining the interpretative weight given to a claim, it
matters less what the doctrine says, and more what courts actually do.
It is true that early nineteenth century patentees drafted claims even
when the formal doctrine gave claims no interpretative weight. But
this was because those patentees had the expectation—an accurate
one—that courts would nonetheless give considerable weight to claims
as a practical matter. 170 Properly understood, nothing in the historical
record contradicts my thesis.
To see why giving claim text no weight over external evidence would
lead to de facto abolition, consider first a situation where the patentee
does not draft a claim, and so the only evidence available to a court is
external evidence. The court would thus take a blind stab at the
optimal scope of the patent based on the external evidence. The result
of this approach will be highly random and arbitrary—the court will
often award too much scope or too little. 171 But the average result
See Posner, supra note 16, at 544 (“Because the parties gain nothing by
putting the marginal promise in the writing, they do not use writings.”).
169 See generally Karl B. Lutz, Evolution of the Claims of U.S. Patents, 20 J.
PAT. OFFICE SOC’Y 134 (1938) (discussing the historical development of
patent claims).
170 John F. Duffy, The Festo Decision and the Return of the Supreme Court
to the Bar of Patents, 2002 SUP. CT. REV. 273, 309-10 (explaining how claims
were given interpretative weight by juries and helped expand patent rights);
see also Posner, supra note 16, at 545 (observing that “even the softest [i.e.
most anti-textualist] courts put more weight on written promises than on oral
promises” as a practical matter).
171 See supra Part II.B.3.
168
38
would be to grant the socially optimal amount of scope, because on
average a court is just as likely to err on one side as on the other. Thus,
as a matter ex ante expectation, the patentee would expect this
amount of monopoly reward, even though there would be a lot of
uncertainty and variation around the average.
Now consider what happens if the patentee writes a claim. The
external evidence available in the case does not change—the patentee
would still file the same specification, and the same experts would still
be available to testify (and their knowledge of the industry and the
technology will be the same). As described in Section A, under the
extreme version of the totality-of-the-circumstances analysis, the court
would therefore still on average grant the socially optimal patent scope,
by using the external evidence to fully counteract whatever drafting
bias the patentee includes in his claim. Thus, the patentee’s ex ante
expected monopoly is the same whether or not he writes a claim.
Because the patentee has no expected gain from writing a claim, but
writing a claim costs money in attorneys’ fees, he will not write a claim.
One might respond that a patentee writing a claim would reduce the
variance in the outcomes, so that a risk-averse patentee would have an
incentive to write a claim. 172 But the variance would decrease only if
courts gave outcome-changing weight to the claim text in at least one
instance (i.e. shifted the outcome because the claim was added), and
that change in the outcome in that one instance would also (slightly)
shift the overall average towards the scope indicated by the claim text,
and away from the optimal scope of the patent. At the extreme, we can
imagine a situation where the court considered only the claim text,
which is equivalent to saying claim text gets 100% of the interpretative
weight. In such a regime, the variance of the results would be low,
because courts will always reach the result indicated by the claim. 173
But the mean around which this variance coalesces is the scope
indicated by the claim text, not the optimal scope of the patent.
Risk-aversion is the standard assumption in economics, and it is the
assumption that I follow here. But see Burk & Lemley, supra note 2, at 1752–
53 (suggesting that patentees prefer ambiguity and uncertainty); cf. John R.
Allison, Mark A. Lemley & Joshua Walker, Patent Quality and Settlement
Among Repeat Patent Litigants, 99 GEO. L.J. 677, 704 (2011) (hypothesizing
that patent owners are risk averse).
173 The variance would not be strictly zero, in that the text itself would not
always specify an outcome for every unforeseen situation. See infra text
accompanying notes 232–233. But the variance will be low because text will
specify an outcome for most situations, especially as the patentee would have
an incentive for high precision if courts always followed the text. See infra
text accompanying notes 176–179.
172
39
C. Balancing Long-run and Short-run Efficiency
What the two stylized examples show is that there is a fundamental
tradeoff between the patent system’s policy goal of minimizing longrun information costs by incentivizing the drafting of claims, 174 and
the patent system’s policy goal of maximizing accuracy in the
individual case. As a practical matter, courts can only seek to achieve
each goal through the mechanism of calibrating the weight they give to
claim text vis-à-vis external evidence, or in other words how textualist
they will be. The dilemma is that the respective policy goals pull in
different directions on this question.
One counterargument is that we have an alternative mechanism to
ensure that patentees write claims: we can invalidate the entire patent
if they fail to write a claim. 175 In other words, we can use the stick of
invalidity rather than the carrot of granting broader-than-optimal
scope to achieve the policy goal of providing long-run incentives for
claim drafting.
In a certain sense this is correct, but in practical terms the stick
approach is not very feasible. We can ensure that patentees write a
claim with the threat of invalidating a patent if they do not. But we
cannot ensure that patentees write a precise claim. 176
By “precision” here, I do not mean whether the patentee writes a
claim that matches the optimal scope of the patent (I use the label
“accuracy” for that question). I mean that we want patentees to write
claims that actually tell us something, i.e. that the claim text should
have some information content and actually take a meaningful position
on patent scope that a decision-maker can evaluate. A counterexample
is a patentee who writes a claim that says “I claim the real invention
disclosed in my patent.” This is a completely accurate claim—it
literally describes the real invention and is not overbroad—but the
claim is very imprecise. The claim is imprecise because it has no
information content; it does not actually take a meaningful position on
patent scope, and it is therefore useless in providing a baseline for
courts to engage in ex post adjustment.
A lurking counterargument here is that all text is inherently
indeterminate and thus conveys no information. I will address this
counterargument in Part IV.
175 See 35 U.S.C. § 112 ¶ 2 (requiring patentees to write at least one claim);
35 U.S.C. § 282(3)(A) (providing a defense of invalidity for violation of § 112).
176 See Star Scientific, Inc. v. R.J. Reynolds Tobacco Co., 655 F.3d 1364,
1374 (Fed. Cir. 2011) (a patentee violates § 112 ¶ 2 only if the claim language
is “insolubly ambiguous”).
174
40
The threat of invalidity is a blunt instrument to ensure precision in
patent claiming. Even if courts can (and do) use invalidity to deter
utterly information-empty claims like the one above, 177 it is impossible
in practice to finely calibrate a regime of invalidity to deter patentees
from using terms such as “approximately” or “near,” which are not
utterly empty but which are still rather vague. 178 Invalidation is an onoff switch—one cannot partially invalidate a claim—and so it is
difficult to adjust incentives to correspond to different degrees of
drafting precision. In contrast, the amount of weight to be given to
claim text vis-à-vis external evidence is more flexible, and is a better
instrument for this purpose.
The bottom line is that the patent system has a long-run policy
interest in incentivizing patentees to write not only a claim, but to
write a precise claim that actually conveys information. 179 And this
conflicts with the interest in getting to the optimal patent scope in an
individual case. The more weight that a court gives to external
evidence, the less precise claims will be over the long run, and the less
information they will convey. Conversely, the more weight that a court
gives to claim text, the more biased the outcome will be in the
individual case, but claims in the long run will be written more
precisely. A court that wished to pursue the most efficient course
overall should balance these competing considerations.
In practical terms, the court should allow some external evidence to
be considered, and it should curb the more egregious instances of
patentee overclaiming by either invalidating the claim or by creatively
construing it down. But it should also give claim text primary weight
in the interpretative calculus, such that the court will to some extent
abide by the claim text even if, as a matter of totality-of-circumstances
evaluation, it would find the ideal scope of the patent to be somewhat
narrower than indicated. The amount of overbreadth that patentees
Intermountain Res. & Eng’g Co. v. Hercules Inc., 163 U.S.P.Q. (BNA)
390, 393 n.2 (C.D. Cal. 1969) (holding an “omnibus” claim of the nature
described to be prohibited).
178 See, e.g., Young v. Lumenis, Inc., 492 F.3d 1336, 1346 (Fed. Cir. 2007)
(claim with the term “near” is not invalid).
179 This also explains the Federal Circuit’s treatment of means-plusfunction claims. See 35 U.S.C. § 112 ¶ 6 (2006) (defining means-plus-function
claims). These claims specify only the function that an invention is supposed
to perform and thus have very little information content. See Burk & Lemley,
supra note 2, at 1774 (explaining that means-plus-function claims are a
remnant of central claiming). Not coincidentally, courts have treated such
claims with extreme disfavor. See James Farrand et al., “Reform” Arrives in
Patent Enforcement: The Big Picture, 51 IDEA 357, 414 (2011) (discussing
how the Federal Circuit has narrowed means-plus-function claims).
177
41
are permitted is effectively the “bribe” that courts give to patentees as
an incentive to write precise claims. 180
As Part IV.A will explain, the balancing act I have described is in
fact basically what courts do already, though the equilibrium has
occurred more as a matter of accident than conscious design. That is,
as the next Part will discuss, the Federal Circuit is presently
comprised of a camp of textualist judges who give a relatively high
amount of weight to claim text, and a camp of non-textualist judges
who more closely follow an equal-weight-to-all-evidence approach. 181
The position of the court as a whole therefore works out to be a
reasonable approximation of the correct balance. But the fact that this
balance occurs through the averaging of a methodological war between
an extremist textualist camp and an extremist non-textualist camp,
rather than a unified approach where everyone is on the same page
about the need for balance, also means there is a lot of extra legal
uncertainty (over and above the efficient uncertainty of a balancing
act) due to the doctrinal conflict.
It should also be noted I am not saying that current practice strikes
the perfect balance, but only that it strikes a reasonable one. Perfectly
calculating the truly optimal tradeoff between short-run accuracy and
long-run incentives—i.e. the optimal bribe to patentees—would involve
the same kind of information difficulty that we have already seen in
attempts to directly calculate the optimal patent scope. For this reason,
I cannot affirmatively state what the optimal bribe is. I only know that
the critics’ apparent position—zero, or close to it—is clearly wrong.
IV. ADDRESSING THE LINGUISTIC INDETERMINACY OBJECTION
To those who are familiar with the patent literature, the first
reaction to my argument that claims provide information to courts is
likely to be tremendous skepticism. After all, claim construction
disputes are extremely common: courts disagree all the time about
what a particular claim means in terms of whether a particular
product infringes a particular patent. 182 The uncertainty surrounding
It is worth mentioning that this analysis also applies to invalidity for
overbreadth as well as claim construction. If courts invalidated a claim
whenever they thought it was even the slightest bit broader than the optimal
scope of the patent, then patentees would again have no incentive to write
claims. Thus, my theory says that courts should hesitate somewhat before
invalidating claims, though they should also invalidate clearly overbroad
claims. Consistent with my theory, this is exactly what courts do in practice.
See Microsoft Corp. v. i4i Ltd. P’ship, 131 S. Ct. 2238 (2011) (reaffirming that
courts give a presumption of validity to issued claims).
181 See infra text accompanying notes 215–226.
182 See supra note 48 and accompanying text.
180
42
claim construction doctrine, in turn, leads to a very common view that
claims are intrinsically indeterminate due to the innate defects of
language. 183 I will call this the “linguistic indeterminacy thesis.”
Under this view, claim text cannot help judges resolve disputes or
reduce information costs, but rather creates more disputes and
increases information costs—because injecting meaningless claim text
into the patent system can only provide clever lawyers with more
make-work to muddy the waters and provoke litigation. 184 In short, it
seems to confirm the critics’ policy prescription that claims should be
abolished either de jure or de facto; because under this view claims can
provide no social benefit and only increase social cost. Not surprisingly,
the linguistic indeterminacy thesis is a central feature of the critics’
articles. 185
A key premise of the linguistic indeterminacy thesis is that frequent
disputes among judges proves the intrinsic indeterminacy of text. 186
This premise is often only implicitly stated by the critics, but it is
essential to their argument. It is also wrong.
A. The Circular Nature of the Objection.
A rare example of someone stating the premise of the argument
explicitly is Dan Burk. According to Burk:
This [high reversal rate] belies the certainty of plain
meaning rules. It is surely not the case that the trial
See, e.g., Autogiro Co. v. United States, 384 F.2d 391, 396 (Ct. Cl. 1967)
(“The very nature of words would make a clear and unambiguous claim a rare
occurrence.”); Arti K. Rai, Specialized Trial Courts: Concentrating Expertise
on Fact, 17 BERKELEY TECH. L.J. 877, 881–82 (2002) (arguing that lay judges
cannot understand technically complex language); Bender, supra note 4, at
209 (arguing “claim language is often inherently ambiguous”).
184 Burk & Lemley, supra note 2, at 1752 (arguing that uncertainties arise
because “lawyers are good at their jobs”); Liivak, supra note 12, at 40
(arguing that claims force courts to engage in a “meaningless exercise”)
185 See, e.g., Burk & Lemley, supra note 91, at 30 (arguing that there is
simply “no such thing” as an ordinary meaning to claim text); Burk, supra
note 12, at 7–11 (same); Lee, supra note 12, at 114 (arguing against a view
that “presumes that language is determinate”); Liivak, supra note 12, at 40
(“Claim interpretation is now a meaningless exercise.”).
186 See, e.g., Burk, supra note 12, at 9 (arguing that judicial disagreement
proves text is indeterminate); Burk & Lemley, supra note 2, at 1744 (arguing
that claim text “isn’t working” because “courts seem unable to agree on what
particular patent claims mean”); Liivak, supra note 12, at 37 (same); Thomas
Chen, Note, Patent Claim Construction: An Appeal for Chevron Deference, 94
VA. L. REV. 1165, 1178–80 (2008) (arguing that judicial conflict demonstrates
“as a matter of logic” that claims have no true meaning).
183
43
judge cannot read the text, or lacks access to a dictionary.
If this were all that were required to reach the plain,
ordinary meaning of claims, then one might expect trial
court claim construction to be upheld with the same
frequency that they are in fact overruled. What is clear is
that plain meaning is not so plain. 187
Burk is far from alone, though he is the most explicit about his
argument. And, at first glance, the argument is quite compelling. If a
district judge, following the textualist methodology, reaches conclusion
X, while an appellate judge following the same textualist methodology
reaches conclusion Y, then either one of the judges has misapplied the
methodology, or the methodology is indeterminate for the particular
case. Given that the textualist methodology is supposed to be easy to
apply, it is unlikely that a judge would accidentally misapply the
methodology. This seemingly leads to the conclusion that frequent
disagreement among judges proves textualism is indeterminate, and
there is accordingly no intrinsic meaning to text.
But Burk’s argument has a crucial assumption: it would be true only
if the appellate and district judges were both actually trying to apply
the textualist methodology. There is no good evidence to justify this
assumption, and much evidence to contradict it. To state my argument
simply, the main reason for frequent claim construction disputes is
that some judges are not following the claim text despite purporting to
do so, and not because the claim text is indeterminate. 188
How do critics like Burk know that all the patent judges are really
trying to follow the textualist methodology? The critics generally rely
on judicial professions to this effect. 189 But such self-serving
statements are unreliable. 190 Textualism is in the political vogue right
now, and every judicial nominee must take a figurative blood oath
before the Senate to practice it, so there is a strong incentive for judges
to pretend to be following plain text even when it is not true.191
Burk, supra note 12, at 9.
Chiang & Solum, supra note 6.
189 See Burk, supra note 12, at 7–8 (“The membership of the Federal
Circuit appears to be dominated by judges who lean toward strong forms of
textualism.”). To the extent that Burk is merely describing judicial rhetoric
and appearances, I would agree. My disagreement is with his implicit
assertion that the court actually is textualist in orientation.
190 See Richard A. Posner, Realism About Judges, 105 NW. U. L. REV. 577,
582 (2011) (“there is no recognized duty of candor in judicial opinion writing”).
191 Id. at 583 (“Judges have political reasons to represent creativity as
continuity and innovation as constraint.”); Robert Alleman & Jason Mazzone,
The Case for Returning Politicians to the Supreme Court, 61 HASTINGS L.J.
187
188
44
When we look at what patent judges do, rather than merely what
they say, it becomes quite obvious that the consideration of external
evidence during claim construction—and hence departure from plain
textual meaning—is pervasive and routine. The Federal Circuit holds
that the specification must always be considered during claim
construction, 192 even while it pretends that courts never “import”
elements from the specification into the claim. 193 Moreover, it refuses
to hear claim construction appeals unless there is a complete record of
external evidence including testimony about the defendant’s accused
product, 194 despite the accused product having no relevance at all to a
textualist analysis of claim language. 195 If claim construction was
actually being carried out as a purely textual exercise—in Burk’s
characterization, of only reading the claim text and looking up a
dictionary—then the Federal Circuit’s practice would be inexplicable.
The most natural way to understand the practice of requiring so much
external evidence to be provided is that the judges—or at least some of
them—use it in reality, even if they deny such use in rhetoric. 196
Moreover, even with the obvious incentives for judicial nontransparency, 197 some Federal Circuit judges have openly admitted
1353, 1376-77 (2010) (“nominees now present themselves as the law’s
servants, robotically applying legal rules to the case at hand”).
192 Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1582 (Fed. Cir.
1996) (“the specification is always highly relevant to the claim construction
analysis”).
193 CollegeNet, Inc. v. ApplyYourself, Inc., 418 F.3d 1225, 1231 (Fed. Cir.
2005) (“In examining the specification for proper context, however, this court
will not at any time import limitations from the specification into the
claims.”). See MERGES & DUFFY, supra note 75, at 820 (stating that these two
rules “fundamentally contradict each other”)
194 Jang v. Boston Scientific Corp., 532 F.3d 1330, 1337–38 (Fed. Cir. 2008).
The Federal Circuit also requires expert testimony about the accused product
in most cases. Centricut, LLC v. Esab Group., Inc., 390 F.3d 1361, 1369–70
(Fed. Cir. 2004).
195 SRI Int’l v. Matsushita Elec. Corp., 775 F.2d 1107, 1118 (Fed. Cir. 1985)
(en banc); NeoMagic Corp. v. Trident Microsystems, Inc., 287 F.3d 1062, 1074
(Fed. Cir. 2002).
196
See Jeffrey A. Lefstin, Claim Construction, Appeal, and the
Predictability of Interpretative Regimes, 61 U. MIAMI L. REV. 1033, 1054
(2007) (“regardless of [ ] the black-letter law . . . , it is reasonable to expect
that judges will test the validity of their interpretations by considering what
outcomes follow”).
197 For those who find my suggestion that judges are not transparent to be
outrageous and defamatory, I plead truth and offer this revealing quote from
Justice Scalia: “I never thought Oliver Wendell Holmes and the legal realists
did us a favor by pointing out that all these legal fictions were fictions: Those
judges wise enough to be trusted with the secret already knew it.” Antonin
45
that they do not follow claim text, but rather rely heavily on external
evidence. Federal Circuit Judge Alan Lourie’s dissenting opinion in
Arlington Indus., Inc. v. Bridgeport Fittings, Inc. 198 provides an
excellent example:
[I]n construing the claims we should avail ourselves of the
knowledge we glean from the patent specification to see
what the inventors disclosed as their invention. The
bottom line of claim construction should be that the
claims should not mean more than what the specification
indicates, in one way or another, the inventors
invented. 199
Thus, Judge Lourie first looks to “the patent specification to see
what the inventors disclosed as their invention,” and the claim will
then be creatively construed so that it does not “mean more than what
the specification indicates, in one way or another, the inventors
invented.” The claim text itself never enters this equation; everything
depends on what the actual invention is. This is a perfect reflection of
the critics’ proposed methodology. In similar fashion, as previously
described in Part I.C.6., Judge S. Jay Plager has candidly admitted to
doing the same thing. 200 More circumspectly, Judge Newman has also
articulated a broad holistic methodology that considers a wide variety
of evidence beyond the patent claim, and consequently appears to give
claim text relatively little interpretative weight:
In our de novo review we have considered the analysis
and conclusions of the district court, as well as the
testimony and opinions of the expert witnesses, in
resolving these questions. . . . [O]ur determination of the
issues on appeal has drawn on the record of the Markman
hearing and the testimony of the expert witnesses,
including their conflicting views of the significance of
various distinctions drawn during patent prosecution with
respect to the prior art, as well as with respect to the
accused Intel methods and their relation to the EMI
method and prior art methods. 201
Scalia, Assorted Canards of Contemporary Legal Analysis, 40 CASE W. RES. L.
REV. 581, 589 (1990).
198 632 F.3d 1246 (Fed. Cir. 2011).
199 Id. at 1258 (Lourie, J., dissenting).
200 Retractable Techs., Inc. v. Becton, Dickinson & Co., 653 F.3d 1296,
1311 (Fed. Cir. 2011) (Plager, J., concurring).
201 EMI Group N. Am., Inc. v. Intel Corp., 157 F.3d 887, 892 (Fed. Cir.
1998). See Timothy R. Holbrook, Substantive Versus Process-Based
Formalism in Claim Construction, 9 LEWIS & CLARK L. REV. 123, 150 (2005)
46
Once again, it is impossible to characterize this methodology as one of
simply reading the claim text and looking up a dictionary. The simple
fact of the matter is that it is routine for courts to consider external
evidence in claim construction.
Sometimes the proponents of the linguistic indeterminacy thesis
seem to recognize this reality, but they do not recognize its logical
implications for their argument. For example, in one passage of his
article with Mark Lemley, Dan Burk himself observes that “courts, as
a practical matter, aren't paying peripheral claim construction [i.e.
claim text] more than lip service.” 202 Burk and Lemley then cursorily
state that this observation helps their argument. 203 But in fact it
fatally undermines it. The core of the linguistic indeterminacy thesis is
that the blame for the uncertainty problems of the status quo lies with
the intrinsic deficiencies of text. 204 But if courts are not actually
practicing textualism and are not actually relying on text to reach
decisions, then one cannot blame textualism or text for the status quo.
Without the assumption that existing patent judges are all (or nearly
all) faithful textualists, the linguistic indeterminacy thesis falls apart.
More deeply, Burk’s error is one that constitutional law scholars
have exposed using what is known as the “interpretation-construction
distinction.” 205 To understand the logical fallacy involved, it is helpful
to first consider an example from outside of patent law. Consider the
first word of the First Amendment to the Constitution: “Congress.” 206
(characterizing this as a “holistic” methodology where “courts would consider
all the relevant evidence as a whole”).
202 Burk & Lemley, supra note 2, at 1783.
203 Id.
204 Burk & Lemley, supra note 2, at 1744–65 (stating that patent law’s
reliance on written claims “isn’t working”); id. at 1791 (arguing that claim
text has “failed catastrophically”); see also Burk, supra note 12, at 5 (“Due to
the inherent ambiguity of language, the boundary remains necessarily
indeterminate.”); see also Cotropia, supra note 64, at 1913; Liivak, supra note
12, at 37.
205 See generally Chiang & Solum, supra note 6 (describing the difference
between interpreting linguistic meaning and construing legal effect);
Lawrence B. Solum, The Interpretation-Construction Distinction, 27 CONST.
COMMENT. 95 (2010); RANDY E. BARNETT, RESTORING THE LOST
CONSTITUTION: THE PRESUMPTION OF LIBERTY 118–30 (2004); KEITH E.
WHITTINGTON, CONSTITUTIONAL CONSTRUCTION: DIVIDED POWERS AND
CONSTITUTIONAL MEANING 5-9 (2001).
206 U.S. CONST. AMEND. I.
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As a matter of intrinsic linguistic meaning, the word cannot be clearer:
it refers to the legislative branch of the federal government. 207
But, as almost every lawyer knows, the legal scope of the First
Amendment is much broader, and its actual boundaries are rather
nebulous. 208 The First Amendment has been broadly construed to
cover all manner of state government action, executive action, and
judicial action; 209 none of which are the actions of the legislative
branch of the federal government.
What proponents of the linguistic indeterminacy thesis do is conflate
these two entirely different concepts of meaning. Under Burk’s logic, 210
the fact that judges disagree with each other about what “Congress”
means as a legal matter—i.e., that they disagree about the scope of the
First Amendment and this causes higher courts to reverse lower
courts—proves that the word “Congress” is linguistically
indeterminate. But it proves no such thing. The fact that judges can
creatively construe the word “Congress” to cover all government as a
matter of legal precedent does not prove that the word is intrinsically
meaningless. All it proves is that judges have lots of power in setting
legal precedent. It is a mistake to conflate judge-controlled legal
meaning with intrinsic linguistic meaning. 211
This logical fallacy is deeply pernicious for patent law because it
results in a self-perpetuating vicious cycle. 212 If we have some judges
who are surreptitiously following the critics’ proposal—i.e. to first look
for the real invention using extrinsic evidence and then creatively
construing the claim text to conform—then these judges are going to
render claim “interpretations” that are distinctly implausible as a
matter of ordinary language. They will creatively construe claim terms
like “screw” (to use Burk and Lemley’s example) to cover only wooden
screws, or alternatively to cover every fastening device, depending on
See Mark P. Denbeaux, The First Word of the First Amendment, 80 NW.
U. L. REV. 1156 (1986) (exploring the disconnect between the textual meaning
and the legal scope of “Congress”).
208 Compare Marsh v. Alabama, 326 U.S. 501 (1946) (holding First
Amendment applied to a privately owned company town) with Lloyd Corp. v.
Tanner, 407 U.S. 551 (1972) (holding that First Amendment does not apply to
a privately owned shopping mall).
209 See, e.g., New York Times Co. v. Sullivan, 376 U.S. 254 (1964) (applying
the First Amendment to state common law libel).
210 See supra text accompanying note 187.
211 There are some potential subtle differences between what one might
consider the “plain” meaning of text and the “linguistic” meaning. See Solum,
supra note 205, at 100–03 (discussing in more detail how linguistic meaning
is discerned). For my purposes here, these differences are immaterial.
212 See generally Chiang & Solum, supra note 6.
207
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what the external evidence indicates the real invention to be. 213 Antitextualist academics then swoop in and argue that these conflicting
judicial decisions prove the word “screw” to be linguistically
indeterminate. 214 From this incorrect predicate, the anti-textualist
argues that courts should interpret hopelessly indeterminate words
like “screw” according to the real invention. 215 Their judicial allies then
take this as encouragement to engage in even more creative
construction to find the real invention, which generates even more
legal uncertainty, which prompts even more academic criticism of
claim text, and so on ad infinitum. A better example of circular
bootstrapping cannot be found.
This vicious cycle is exactly what has happened in patent law. A
good example is the outcome in Retractable Techs., Inc. v. Becton,
Dickinson & Co., 216 the case in which Judge Plager wrote his
concurring opinion. The ultimate holding of the case was that a claim
to a syringe with a “body” would cover only syringes using a singlepiece structure, and did not cover a later two-piece syringe. As the
majority opinion (by Judge Lourie) conceded, a purely textual analysis
of the word “body” would suggest that it covers both one-piece and
multiple-piece structures. 217 The court adopted the narrower
construction, however, because the majority believed that a singlepiece syringe was more reflective of “the scope of the actual
invention.” 218 In other words, the majority construed the word “body”
in a way that departed from its plain meaning. They did this not
because they could not determine what the plain meaning was, but
Burk & Lemley, supra note 91, at 37 (using the word “screw” as an
example of indeterminacy).
214 Id. I do not mean to single out Burk or Lemley. This fallacy pervades
the patent law scholarship. Another explicit example is Peter Lee, who
argues that because “traditional claim construction”—i.e. doctrine—is
indeterminate, courts must necessarily look beyond claim text. Lee, supra
note 12, at 113. Once we separate legal meaning from intrinsic meaning, the
logical error is plain.
215 See, e.g., Liivak, supra note 12, at 40 (arguing that courts must look to
the real invention or claims would have no meaning); Lee, supra note 12, at
113 (arguing that courts have no choice but to in look to economic balancing
when claims are indeterminate); Burk & Lemley, supra note 91, at 52–54
(arguing that there is no such thing as plain meaning and courts must
instead engage in a policy analysis of ideal patent scope).
216 653 F.3d 1296 (Fed. Cir. 2011).
217 Id. at 1305 (conceding that the claim text itself would “imply that a
‘body’ is not limited to a one-piece structure,” but holding that “the claim
construction process entails more than viewing the claim language in
isolation”).
218 Id.
213
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because the majority gave preference to the external-evidencedetermined result.
The majority’s decision then prompted a furious dissent by Chief
Judge Rader, who argued that the plain meaning of “body” ought to be
followed. 219 In this way, Retractable demonstrates how legal
uncertainty can arise even in the absence of any linguistic
indeterminacy. Retractable contains legal uncertainty for two reasons.
First, the majority’s look-for-the-real-invention methodology is
inherently uncertain, because nobody knows ahead of time what level
of abstraction a particular judge will find to be the real invention, and
different judges may well have very different intuitions on how much
patent scope is optimal in a particular case. 220 Second, and more
importantly, the majority creates a methodological conflict with more
textualist-oriented judges, 221 and nobody knows ahead of time whether
they will get an appellate panel comprised of textualist judges or nontextualist judges. 222 And, going forward, Retractable stands as a citable
precedent for the proposition that external evidence is an acceptable
interpretative methodology; which will cause even more
methodological conflict and legal uncertainty in the future,
perpetuating the vicious cycle.
Retractable is hardly an isolated case in proving that the cause of
judicial disagreement over claim construction is conflict over doctrinal
methodology, not over the intrinsic meaning of claim text. 223 Consider
the leading modern claim construction case, Phillips v. AWH Corp. 224
In Phillips, the majority, citing a stipulated dictionary definition,
construed the word “baffle” to cover all objects that “check, impede, or
obstruct the flow of something.” 225 Judge Lourie, this time in dissent,
Id. at 1311–12 (Rader, C.J., dissenting).
Royal Typewriter Co. v. Remington Rand, Inc., 168 F.2d 691, 693–94
(2d Cir. 1948) (Hand, J.) (“courts have differed, and always will differ, as to
the allowable latitude in a given instance”).
221 See Retractable Tech., Inc. v. Becton, Dickinson & Co., 659 F.3d 1369,
1373 (Fed. Cir. 2011) (Moore, J., dissenting from denial of en banc rehearing)
(criticizing “the majority’s attempt to rewrite the claims to better conform to
what it discerns is the ‘invention’ of the patent”).
222 See R. Polk Wagner & Lee Petherbridge, Is the Federal Circuit
Succeeding? An Empirical Assessment of Judicial Performance, 152 U. PA. L.
REV. 1105, 1161-63 (2004) (finding that claim construction decisions are
panel dependant).
223 Retractable, 659 F.3d at 1373 (Moore, J., dissenting from denial of en
banc rehearing) (arguing that Retractable “illustrates a fundamental split
within the court as to . . . the proper approach to claim interpretation”).
224 415 F.3d 1303 (Fed. Cir. 2005) (en banc).
225 Id. at 1324.
219
220
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argued that “baffles” should cover only “bullet deflecting baffles,”
because that was how the specification described the purpose of the
invention. 226 Once again, the disagreement and uncertainty is purely
about legal methodology. Everyone knew what “baffle” meant as a
textual matter. Indeed, it was so clear that the parties stipulated to
it. 227 The question was only whether the linguistic meaning would
govern as a legal matter. And the fact that judges disagree about legal
methodology cannot properly be invoked as proof that a particular side
in the debate (i.e. the look-for-the-real-invention side) is correct.
At this point, a countervailing concern might be that I have
undermined my own theory: if courts are already in fact practicing a
creative construction methodology at least some of the time, then
shouldn’t that undermine the incentive for drafting and destroy the
information value of claims? And if those consequences have not
occurred, then isn’t my theory wrong? The answer this concern is found
in Part III. I do not argue that courts should never consider external
evidence, nor that they cannot ever engage in creative construction. 228
My argument is that they cannot give external evidence too much
weight and cannot engage in creative claim construction too often, and
certainly not with the weight and frequency that critics of claims
would like. The fact that courts sometimes engage in creative
construction now is in fact predicted by my theory, because ultimately
courts should balance the long run savings in information costs against
the short-run inaccuracy costs of enforcing slanted text. The right
outcome under this approach is not to mechanically abide by claim text
in every case; but neither is it to give no weight to claim text
whatsoever. What courts do today is a reasonable approximation of the
right balance.
This observation leads to a second potential concern: If courts are
striking roughly the right balance under my theory, then why is claim
construction litigation so unpredictable? (And I acknowledge that
claim construction litigation is unpredictable.) In other words, if Burk
and Lemley cannot properly blame textualism for the uncertainty
problems of the status quo because courts are not actually practicing
textualism, then can’t they at least blame my theory, given that I am
arguing that courts in fact practice the kind of balancing that my
theory prescribes?
Id. at 1329 (Lourie, J., dissenting).
Id. at 1324 (noting that the parties had stipulated on what the
dictionary definition of “baffle” was).
228 See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S.
722, 732 (2002) (“the clearest rule of patent interpretation, literalism, may
conserve judicial resources but is not necessarily the most efficient rule”).
226
227
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It is true that some amount of uncertainty is part of my theory, and
to that extent the counterargument would be on target. But the
present degree of uncertainty in claim construction doctrine is far more
than what my theory would find efficient. This is because the pervasive
methodological conflict that we have witnessed is wholly wasteful from
the perspective of achieving an efficient balance between long run and
short run considerations. As a matter of first principles, we can achieve
a proper balance between long-run incentives and short-run accuracy
in two ways: We can have all the judges agree on the need for balance
and agree on the relative weight to be given to claim text vis-à-vis
external evidence; or we can have a methodological war between
textualist judges and non-textualist judges, with each camp sticking to
their own preferred methodology in their own particular cases, 229 and
the overall average working out to be something that is about right. It
should be quite evident that the latter approach will create a lot more
doctrinal conflict and legal uncertainty than the former approach. And
the latter approach is exactly what has been happening in the Federal
In this sense, the courts are currently striking
Circuit. 230
approximately the right balance under my theory, but they are doing it
in the worst way possible. The extra uncertainty caused by this
methodological conflict is not efficient or desirable, though a
mechanism to solve that problem—i.e. to force life-tenured judges to
agree and compromise on interpretative methodology—eludes me.
Within the realm of the possible, the status quo may be close to the
best that can be achieved.
B. Under-determinacy Versus Indeterminacy.
A second response to the indeterminacy objection is that there is an
important difference between saying that claim text is indeterminate
and saying that it is under-determinate. 231 Judicial conflict and
disagreement can at most prove that claim text is under-determinate,
not that it is indeterminate.
Some definitions are helpful here. A text has a fully determinate
linguistic meaning if it specifies a single right answer in every factual
Wagner & Petherbridge, supra note 222, at 1161–63 (finding that the
interpretative methodology used depends on the identity of the judge).
230 See Retractable Tech., Inc. v. Becton, Dickinson & Co., 659 F.3d 1369,
1373 (Fed. Cir. 2011) (Moore, J., dissenting from denial of en banc rehearing)
(observing that there is a “fundamental split within the court”); MERGES &
DUFFY, supra note 75, at 820 (arguing that that the two doctrinal rules
pertaining to the specification’s role in claim construction “fundamentally
contradict each other”).
231 Lawrence B. Solum, On the Indeterminacy Crisis: Critiquing Critical
Dogma, 54 U. CHI. L. REV. 462, 462-470 (1987).
229
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situation (which, for purposes of my analysis here, I will assume that
judges actually follow). A text is indeterminate and intrinsically
meaningless if it specifies no right answer in any factual situation.
Finally, a text is under-determinate if it specifies a right answer in
some factual situations.
The notice theory posits that claim text is fully determinate. 232 In
this respect, the critics are right that it is too ambitious. Few if any
texts are fully determinate, because it is difficult to craft textual rules
that prescribe an answer for every factual situation that might arise.
To take H.L.A. Hart’s famous example, even a garden variety rule such
as “no vehicles in the park” is not fully determinate, because there is
some vagueness about what constitutes a “vehicle” in terms of whether
it covers bicycles. 233 In similar fashion, a patent claim to a new type of
“vehicle” will contain the same vagueness about its scope.
But saying that a text is not fully determinate does not imply that
the text is therefore indeterminate. The word “vehicle” does not
prescribe a right answer in the case of a bicycle. But an automobile is
clearly a vehicle and therefore violates the rule, while a pedestrian
clearly is not a vehicle and does not violate the rule. 234 A textual
command such as “no vehicles in the park” is therefore underdeterminate. This under-determinacy will cause uncertainty and
judicial disagreement, because even judges who faithfully attempt to
follow text will disagree about whether a cyclist is guilty of violating
the prohibition, 235 and such hard cases will disproportionately emerge
in litigation due to selection effects. 236 The existence of frequent
judicial disagreement and litigation uncertainty thus does not prove
that a text is indeterminate. At most it proves that the text is underdeterminate.
And if claim text is only under-determinate rather than
indeterminate, then the force of the indeterminacy objection dissipates.
An under-determinate text still has social value, because it specifies an
answer in some situations and provides some amount of information to
Merrill v. Yeomans, 94 U.S. 568, 573 (1876) (“no excuse” for uncertainty
in claim language).
233 H.L.A. Hart, Positivism and the Separation of Law and Morals, 71
HARV. L. REV. 593, 607 (1958).
234 Id.
235 Id.
236 Richard S. Gruner, How High Is Too High?: Reflections on the Sources
of Claim Construction Reversal Rates at the Federal Circuit, 43 LOY. L.A. L.
REV. 981, 985 (2010); see generally George L. Priest & Benjamin Klein, The
Selection of Disputes for Litigation, 13 J. LEGAL STUD. 1 (1984) (describing
selection effects).
232
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courts. It is therefore not fair to say that the patent system’s reliance
on claim text is explicable only as a cult-like devotion to mindless
formalism, a view that often underlies the critics’ arguments. 237 Nor
does an under-determinate text induce rather than resolve litigation
disputes or increase rather than decrease cost: An under-determinate
text that specifies some answers to some situations is still better than
an utterly indeterminate legal standard such as “substantial
similarity,” or the de facto arbitrariness that will result from taking
blind stabs in the dark on the ultimate question of optimal patent
scope.
CONCLUSION
This Article began with a simple but surprisingly unasked question:
why does the patent system allow patentees to write their own claims?
The answer, it turns out, gives us some important insights into the
fundamental operation of the patent system. The basic reason is that
the government (acting through judges or the PTO) cannot directly
determine the proper scope of a patent because it does not have
information about the social benefits and costs of a patent. Indeed, this
fundamental information difficulty is the reason for having a patent
system at all.
Once we recognize this fundamental information difficulty, the
value of patentee-written claims becomes more clear. Patentees have
the information that courts do not, and claims are an informationforcing mechanism designed to overcome this asymmetry. Requiring
patentees to write claims forces them to partially disclose their private
information and to state an initial baseline that courts can then more
meaningfully scrutinize. The claim will surely be imperfect, but it is
better than having courts—or any other government actor—take blind
stabs in the dark on the correct scope of the patent.
Establishing that patentee-written claims have social value then
leads to several important implications for the long running debate
over claim construction. Most obviously, it means that courts should
not abolish or ignore claims entirely, contrary to what prominent
scholars have argued. Moreover, claims cannot even be given equal
See Liivak, supra note 12 (describing reliance on claims as a “cult”);
Peter Lee, Patent Law and the Two Cultures, 120 YALE L.J. 2, 31 (2010)
(arguing that judges are “cognitive misers” who adopt “hypertextualism” in
claim construction because they are afraid of technology); Dan L. Burk &
Mark A. Lemley, Policy Levers in Patent Law, 89 VA. L. REV. 1575, 1672
(2003) (arguing that the Federal Circuit is overly formalistic). The argument
is also wrong to the extent that it assumes that Federal Circuit judges are
actually practicing formalist methods. See supra Part IV.A; Tun-Jen Chiang,
Formalism, Realism, and Patent Scope, 1 IP THEORY 88 (2010).
237
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treatment with other types of evidence. As the Article has explained,
claim text must be given primary (though not conclusive) weight in the
claim construction calculus, in order to preserve the long-run incentive
of patentees to write claims. And this is in fact what courts have done.
The contribution of this Article is thus not only to answer an
interesting theoretical puzzle, but also to provide a positive and
normative theory for the long-running debate over claim construction
doctrine.
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