“An Idea Can Be Like Nothing But An Idea”—Another Try
1. Introduction
The fundamental premise of Berkeley’s idealism is that the things we perceive by
our senses are only ideas. But Berkeley knew that even philosophers who accept this
premise would propose ways to avoid the idealistic conclusions that he drew from it.
Chief among those ways was the representational theory of perception, commonly
attributed to Locke and to Descartes, according to which ideas are representations of
material things. The ideas represent the things, it was held, chiefly by virtue of
resembling the things’ primary qualities. If this theory is right, then idealism is false.
Accordingly, in Principles I sec. 8 and in a corresponding passage in Three Dialogues
Between Hylas and Philonous, Berkeley attempts to demolish the representational theory
of perception, by invoking what has come to be called his “Likeness Principle” (hereafter
referred to as “LP”). The purpose of this paper is to examine this part of his attack on the
representational theory.
In 1965, David Armstrong described Berkeley’s argument in section PHK sec. 8
as “extremely ingenious, probably valid, but seldom considered.”i There have in fact been
several discussions of LP since 1965. In 1966, Phillip Cummins published a classic paper
“Berkeley’s Likeness Principle,” that attempts to explicate LP in terms of three
metaphysical principles.ii George Pitcher argued in his 1977 book, Berkeley, that
Berkeley has no cogent grounds for LP.iii I offered a reconstruction and a critique of
Berkeley’s argument for LP in a 1985 paper, “An Idea Can Be Like Nothing But An
Idea,” that also criticized both Pitcher’s and Cummins’s treatments.iv In his 1989 book,
Berkeley: An Interpretation, Kenneth Winkler criticized Cummins’s account in much the
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same way as I, and offered a different account of Berkeley’s argument for LP.v More
recently (2006), Todd Ryan has published a paper in this journal, “A New Account of
Berkeley’s Likeness Principle,” that criticizes my account as well as Cummins’s and
Winkler’s, and that proposes yet another analysis of Berkeley’s case for LP.vi I shall not
review this entire debate in this paper, for it seems to me that Ryan does a fine job of
reviewing and supplementing my and Winkler’s critiques of Cummins’s account as well
as of criticizing Winkler’s positive account. Rather, I shall present an improved version
of my 1985 reconstruction and assessment of Berkeley’s argument. In section 2, I analyze
the structure of PHK sec. 8 and evaluate what I take to be one of the two objections to
representationalism that Berkeley offers in it. In section 3, I review my original
reconstruction of Berkeley’s argument for LP, expound Ryan’s criticism of it, and present
a revised version that avoids the difficulty he raises. In section 4, I offer a brief critique of
Ryan’s positive account. In section 5, I show that the argument for LP is ineffective
against any version of representationalism that distinguishes between immediate
perception and perception tout court.
2. Berkeley’s two-pronged rebuttal of representionalism in PHK I sec. 8
Section 8 has two parts, which provide two different, complementary rebuttals of
representationalism, and which I shall call “A” and “B” for convenience,vii
A
But, say you, though the ideas themselves do not exist without
the mind, yet there may be things like them, whereof they are
copies or resemblances, which things exist without the mind in
an unthinking substance. I answer, an idea can be like nothing
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but an idea; a colour or figure can be like nothing but another
colour or figure. If we look but never so little into our thoughts,
we shall find it impossible for us to conceive a likeness except
only between our ideas.
B
Again, I ask whether those supposed originals or external things,
of which our ideas are the pictures or representations, be
themselves perceivable or no? If they are, then they are ideas and
we have gained our point; but if you say they are not, I appeal to
any one whether it be sense to assert a colour is like something
which is invisible; hard or soft, like something which is
intangible; and so of the rest.
The key claim of part A is that an idea can resemble only an idea; the key claim of part B
is that something perceivable cannot resemble something unperceivable. In the First
Dialogue, Berkeley seems to amalgamate A and B, for he has Philonous say:
But how can that which is sensible be like that which is
insensible? Can a real thing in itself invisible be like a color; or a
real thing which is not audible, be like a sound? In a word, can
anything be like a sensation or idea, but another sensation or
idea? (W2: 206)
Here Philonous’ first two rhetorical questions assert B and his third rhetorical question
asserts A, but his use of “in a word” runs the first two questions together with the third.viii
Still, A and B are distinct points, so I shall discuss them separately.
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I start with B, because it calls only for a brief discussion. B is plainly directed
against any version of representationalism that holds that material things are
unperceivable and that only ideas are perceivable. Locke sometimes seems to embrace
such a view, and it was a commonplace throughout the modern period.ix It seems to me
that insofar as Berkeley’s target is this version of representationalism, he is entirely
successful in demolishing it. Something that is perceivable cannot resemble something
that is unperceivable, at least if we take “unperceivable” to mean “unperceivable in
principle” (unperceivable even with the aid of the most powerful instruments that could
ever exist), as opposed to “unperceivable in fact” (unperceivable even with the aid of the
most powerful instruments currently available).
However, a representationalist need not accept Berkeley’s premise that only ideas
are perceivable in this unqualified form; instead, she can hold that only ideas are
immediately perceivable. Whether this qualified version of the premise can lead to the
conclusion that only ideas are perceivable tout court, and hence to the further conclusions
that material things are unperceivable and so cannot resemble ideas, depends crucially on
what “immediately perceivable” means, and more will be said about the notion of
immediate perception in section 4. But for the moment, it suffices to say that from the
premise that only ideas are immediately perceivable, it does not straightforwardly follow
that material things are not perceivable, nor therefore, that they cannot resemble ideas. So
Berkeley’s B, while very ingenious and correct so far as it goes, does not by itself refute
any version of representationalism that distinguishes between perception tout court and
immediate perception.
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Are matters any different when it comes to passage A? Here we should first note
that if A is correct, then it demolishes virtually all, if not all, versions of
representationalism. For virtually all, if not all, representationalist theories hold that ideas
represent material things by virtue of resembling (at least the primary qualities of) those
things. But passage A contains the following argument:
An idea can be like nothing but an idea.
___________________________________
 An idea cannot resemble a material thing.
The premise of this argument is of course just Berkeley’s way of expressing LP. The
importance of LP for Berkeley’s idealism is nicely captured in a remark by E. B. Allaire:
Berkeley’s contemporaries … would not have been thrown off
balance by Berkeley’s claim that sensible objects are composed
of ideas and thus cannot exist unperceived; but they would have
been deeply upset by the so-called likeness principle that
Berkeley put forth in Sect. 8; for it is that principle that
undercuts representative realism. The principle is thus an
essential part of Berkeley’s argument for idealism.x
Yet, passage A gives only the barest indication of why Berkeley thinks LP is true; it
seems to treat LP as virtually self-evident or axiomatic. Thus, one may be tempted to
think that LP rests simply on the idea that something mental cannot resemble something
non-mental. As Phillip Cummins points out, however, this would not do justice to
Berkeley’s thought:
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It is not being claimed that something mental cannot resemble
something non-mental, where “mental” is left vague, as “the only
thing like an idea is an idea” suggests. Rather, Berkeley’s claim is a
colour cannot be like a non-colour, a shape cannot be like a nonshape and a sound cannot be like a non-sound.xi
Furthermore, if the claim that something mental cannot resemble something non-mental
were all there was to LP, then the principle would be open to an obvious objection, which
is well put by George Pitcher:
Why can’t a mental image of a piano, say, be “like”—i.e.,
resemble—a piano, in the perfectly straightforward way in which a
painted picture of a piano is like a piano? Looked at in this way,
Berkeley’s dictum that an idea can be like nothing but an idea
seems as false as the claim that a picture can be like nothing but a
picture.xii
Pitcher’s objection shows that LP is not obviously true; it needs to be argued for. In what
follows, I propose to reconstruct and to assess Berkeley’s argument for LP.
3. Berkeley’s case for the Likeness Principle
Why does Berkeley hold his Likeness Principle? Like Cummins, I take my clue
from the only reason that Berkeley himself gave for it in his published work: “An idea
can be like nothing but an idea; a colour or figure can be like nothing but another colour
or figure [my italics].” The remark after the semicolon, it seems quite clear, is the
premise of an (enthymematic) argument whose conclusion is “an idea can be like nothing
but an idea”—LP. Evidently, then, Berkeley thought that he could derive LP from the
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highly plausible proposition that a color can resemble only a color, a shape only a shape,
a sound only a sound, a smell only a smell, a taste only a taste. This proposition can be
put as a categorical one, as follows:
(0) All sensible qualities of any sort are things that can resemble
only sensible qualities of the same sort.
In my 1985 paper, I claimed that the argument for LP could be built upon (0). But in
order to keep the argument uncluttered, I started instead from the weaker premise that
(1) All sensible qualities are things that can resemble only sensible
qualities.
It is clear that although (1) does not entail (0), (0) entails (1). So if (1) entails LP, so does
(0). The main interpretive project of my paper was to show that (1), when combined with
two other premises held by Berkeley, does entail (a slightly but harmlessly restricted
version of) LP. Those two other premises are:
(2) All sensible qualities are ideas
and
(3) All ideas of sense are sensible qualities.
Propositions (2) and (3) constitute what I called Berkeley’s “Ideaism”—his identification
of sensible qualities with (a certain range of) ideas. This doctrine is assumed from the
outset of the Principles, though it is argued for at length in the First Dialogue. It is
important to note, then, that there is nothing question begging or otherwise illegitimate in
using (2) and (3) in reconstructing an argument that Berkeley does not advance until
section 8 of the Principles. In trying to reconstruct Berkeley’s line of thought, it is
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legitimate to use (2) and (3), since those are premises he assumes to be true at this stage
of his overall argument for idealism.
A note is in order about the qualification “of sense” in premise (3). This
qualification is necessary, because Berkeley would not accept an unqualified version of
(3), viz. that “all ideas are sensible qualities.” For some ideas, namely those that he says
are “formed by help of memory and imagination” and those “perceived by attending to
the operations of the mind” (PHK I, sec. 1), are not sensible qualities for Berkeley.
It might be objected that Berkeley would not accept premise (3) even with its
restriction to ideas of sense, because an idea had during a hallucination or a vivid dream
would be an “idea of sense” but not a “sensible quality.” The answer to this objection is
that Berkeley does not classify ideas had in hallucinations and dreams as “ideas of
sense.” There are many passages where he indicates that “ideas of sense” are only those
regular, coherent ones (caused by God) that for him constitute physical objects; for
instance he says, “the ideas of sense are allowed to have more reality in them, that is, to
be more strong, orderly, and coherent than the creatures of the mind” (PHK I sec. 33;
see also PHK I secs. 29, 30, 36, 90). To cite such passages is of course not to show that
Berkeley’s way of distinguishing between “ideas of sense” and “creatures of the mind” is
unproblematic, But the passages do show that his distinction cannot be obviated merely
by pointing out that at times ideas had in hallucinations and dreams are indistinguishable
from those had in perception, For this ignores Berkeley’s way of making the distinction
between “appearance” and “reality,” which is in terms of an idea’s relations to other
ideas. Furthermore, it assumes that objects with different statuses (i.e. Berkeley’s
“sensible things” or realities and his “creatures of the mind” or appearances) cannot be
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phenomenologically indistinguishable—an assumption on par with assuming that a wax
apple cannot look exactly like a real apple.
Assuming then that Berkeley would accept premises (1)-(3), the interpretive
project of my 1985 essay was to derive LP from this set of premises. Let me review the
reasoning. Suppose we start by formulating LP as a categorical proposition: “All ideas
are things that can resemble only ideas.” It is obvious that one cannot derive this
proposition from premises (1)-(3), since the term “ideas” is distributed in it but not in
them. But one can derive a version of LP that is restricted to the ideas of sense, in the
following way. From (1) and (3), it follows that
(4) All ideas of sense are things that can resemble only sensible
qualities.
But from premise (2) alone, it follows that
(5) All things that can resemble only sensible qualities are things
that can resemble only ideas.
The inference from (2) to (5) is of course valid, since it is of the same form as the
inference from “all horses are animals” to “all heads of horses are heads of animals,” or
from “all cows are mammals” to “all creatures that resemble only cows are creatures that
resemble only mammals.” But from (4) and (5), we can deduce the conclusion that
(6) All ideas of sense are things that can resemble only ideas.
Admittedly (6), unlike LP itself, is restricted to the ideas of sense. But this is no
objection to the reconstruction, because the ideas of sense are the only ones for which LP
needs to be demonstrated. For the only other sorts of ideas that Berkeley recognizes are
ideas “excited in the imagination” (whether voluntarily as in fantasizing or involuntarily
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as in dreams or hallucinations), and ideas of the “passions and operations of the mind”
(Locke’s “ideas of reflection,” which are accessed by introspection). But the former are
merely copies or images of the ideas of sense (PHK I, sec. 33). So the above argument
extends to them as well: if ideas of the imagination can resemble only ideas of sense and
ideas of sense can resemble only ideas, then ideas of imagination can resemble only
ideas. And Berkeley would have regarded it as obvious without proof that an idea had by
introspection can resemble only another idea.
Before turning to Todd Ryan’s objection to this reconstruction, I must note that it
has a flaw. As just mentioned, Berkeley holds that the ideas of imagination are copies of
ideas of sense. This entails that ideas of sense can resemble something other than sensible
qualities, namely, ideas of imagination. But in that case, step (4)—“All ideas of sense are
things that can resemble only sensible qualities”—is false, at least by Berkley’s lights.xiii
Further, since (4) is derived from (1) and (3), at least one of those propositions must be
one that he would regard as false. The amended reconstruction that I shall offer below
will not have this flaw.
I turn now to Ryan’s critique. Ryan argues that although the derivation of LP
from premises (1)-(3) is valid and those premises are ones that Berkeley “probably
accepts,” my reconstruction “fails to explain why Berkeley endorses LP.”xiv The reason
why it fails, he writes, is that “Locke would certainly deny (1), since his position is
precisely that it is possible for a sensible idea (say, the idea of extension) to resemble
something that is not itself a sensible idea.” Now this remark, which at first glance might
seem not to contradict (1), really does contradict (1), because the relation of resemblance
is symmetrical, so that if a sensible idea can resemble something that is not itself a
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sensible idea, but presumably a sensible quality instead, then a sensible quality can
resemble something other than a sensible quality, namely an idea of a sensible quality—
which contradicts (1)’s claim that a sensible quality can resemble only a sensible quality.
Thus Ryan’s point, I take it, is that (1) simply begs the question against Locke, because
Locke would say that a sensible quality certainly can resemble something that is not a
sensible quality, namely an idea of that quality. If this is what Ryan means, then he is
right; for Locke’s representationalism holds precisely that the ideas of certain sensible
qualities--the ideas of primary qualities--do resemble those qualities.
Ryan also elaborates on his objection, as follows:
The problem, I think, is that Dicker begins with what is relatively
non-controversial, viz. that a figure can be like nothing but a figure,
but this initial plausibility is lost in the translation to (1), since the
crucial dispute between Berkeley and the representationalist realist
concerns whether, for example, all figures or shapes must be
sensible. It is at least not obvious that this must be the case. George
Pitcher puts the latter point nicely, observing that
[Locke] could agree that a figure can be like nothing
but another figure—and then add: But of course
Lockean material objects do have figures … and so,
as I have always maintained, our ideas of sense do
resemble material objects with respect to figure and
the other primary qualities.
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Thus, although Dicker does provide a valid deduction of LP from a
set of principles which Berkeley probably accepts, his explanation
is unenlightening in so far as it offers no insight into Berkeley’s
reasons for subscribing to the argument’s crucial premise.xv
This elaboration digresses from Ryan’s charge that premise (1) begs the question
against Locke. Furthermore, it seems to me that Berkeley has a ready and powerful
response to the objection that some figures or other sensible qualities might be insensible
(unperceivable). He would respond by recurring to his point, made in passage B and by
Philonous in the First Dialogue, that if the figures and other primary qualities possessed
by Lockean material objects are really unperceivable, then they cannot resemble ideas,
because something that is (in principle) unperceivable cannot possibly resemble
something that is perceivable. That is the insight on which his rebuttal in passage B of
forms of representationalism that subscribe to the doctrine of the unperceivability of
material things turns, and I find it hard to dispute.
Let me return, then, to what I regard as Ryan’s more important objection, namely
that Locke and his ilk would just reject premise (1). I concede that this objection shows
that (1) is not a premise on which Berkeley can build a successful argument for LP.
However, he could start instead from an amended version of (1):
(1a) All sensible qualities are things that can resemble only sensible
qualities and ideas of sensible qualities.
This proposition captures what is plausible in Berkeley’s premise that a “colour or figure
can be like nothing but another colour or figure,” and it begs no questions against Locke.
Furthermore, an argument for LP that closely parallels the above reconstruction can be
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built on (1a), as follows. Just as Berkeley would accept premise (2) above—that “all
sensible qualities are ideas”—so he would surely accept the premise that
(2a) All sensible qualities and ideas of sensible qualities are ideas.
As we have seen, it also a fundamental the premise of his thought that
(3) All ideas of sense are sensible qualities.
Now from (1a) and (3), it follows that
(4a) All ideas of sense are things that can resemble only sensible
qualities and ideas of sensible qualities.
Notice that (4a), unlike (4) (“All ideas of sense are things that can resemble only sensible
qualities”), allows that ideas of sense can resemble ideas of imagination, since those are
precisely the “ideas of sensible qualities” referred to in (4a). Thus, the use of (4a) corrects
the flaw in (4), viz. that (4) overlooks the point that for Berkeley ideas of sense can
resemble ideas of imagination. But now the reconstruction can be completed on the same
model as my original one. From (2a) alone, it follows that
(5a) All things that can resemble only sensible qualities and ideas of
sensible qualities are things that can resemble only ideas.
Finally, from (4a) and (5a), it follows as before that
(6) All ideas of sense are things that can resemble only ideas.
It is possible to give a structurally similar but simpler reconstruction of Berkeley’s
argument for LP, by interpreting his remark that “a colour or figure can be like nothing
but another colour or figure” more freely than I have done so far. The remark could be
interpreted as implying that
(A) What is perceivable can be like only something perceivable.
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Such an interpretation is not far-fetched, especially in light of what Berkeley says in
passage B: “I appeal to anyone whether it be sense to assert a colour is like something
invisible; hard or soft, like something intangible; and of the rest.” I have said that this
remark should be seen as a direct attack on the doctrine that ideas can resemble things
that are unperceivable in principle. However, when interpreted in the light of (A), it also
allows us to deduce that the only thing an idea can resemble is another idea. For
Berkeley’s “Ideaism” can be concisely formulated as asserting that:
(B) Whatever is perceivable is an idea
and
(C) Whatever is an idea is perceivable.xvi
But LP can be straightforwardly deduced from these three premises. For from (A) and
(C), it follows that
(D) Whatever is an idea can be like only something perceivable.
Further, from (B) alone it follows that
(E) Whatever can be like only something perceivable can be like
only an idea.
Finally, from (D) and (E) it follows that
(F) Whatever is an idea can be like only an idea
which is equivalent to Berkeley’s dictum that “an idea can be like nothing but an idea.”
In summary, then, LP can be derived from a very plausible premise about
resemblance suggested by Berkeley’s aphoristic remark that “a colour or figure can be
like nothing but another colour or figure,” conjoined with his “Ideaism”--his doctrine that
sensible qualities are identical with (a certain range of) ideas. Alternatively, it can be
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derived from an equally plausible premise about resemblance suggested by the same
remark taken together with his rhetorical questions, “whether it be sense to assert a colour
is like something invisible; hard or soft, like something which is intangible; and so of the
rest,” conjoined with “Ideaism,” concisely formulated as the doctrine that all and only
ideas are perceivable.
4. Ryan’s account of Berkeley’s argument for LP
Ryan’s interpretation of Berkeley’s case for LP turns on a metaphysical doctrine
that Ryan claims to find in Locke, namely the doctrine that relations are essentially minddependent. Ryan quotes a number of passages from Locke’s Essay that seem to endorse
such a view, notably this one: “The nature therefore of relation, consists in the referring,
or comparing two things, one to another; from which comparison, one or both comes to
be denominated” (Essay II.xxv.5). Underscoring what Locke seems to be saying here,
Ryan writes: “Notice that Locke’s claim is that it is part of the very nature of relations
that they involve a mental act of comparison between our ideas, and thus are, in an
important sense, mind-dependent entities.”xvii Ryan adds that
In turning to Berkeley’s account of relations, we find that he has
disappointingly little to say about them either in his published or
unpublished works. However, what little he does say suggests that, at least
with respect to the essential mind-dependence of relations, he is wholly in
agreement with Locke. At PHK 142 Berkeley argues that it is impossible
to have an idea of a relation because the latter involves an act of mind, and
as Berkeley argues at length, ideas are altogether passive and inert and
therefore cannot represent a thing that is active. He writes: “all relations
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including an act of the mind, we cannot so properly be said to have an
idea, but rather a notion of the relations or habitudes between things.”
Ryan then says:
Given this account of relations, an alternative reading of
[Berkeley’s] argument suggests itself. If resemblance is taken to
be a relation between two objects, and if relations essentially
involve a mental act of comparison, then a necessary condition
of two things resembling one another is that they either are or
have been the object of a mental act of comparison. If one can
compare only what one directly perceives, and the only thing
one directly perceives are one’s own mind-dependent ideas, it
follows that an idea cannot resemble an unperceived material
object, because only ideas can stand in a relation of resemblance;
or, in other words, ‘an idea can be like nothing but an idea.’xviii
This reasoning can be formulated as follows:
(1) Resemblance is a relation between two objects.
(2) Relations can obtain only between things that are or were
compared.
(3) Resemblance can obtain only between things that are or were
compared. (1, 2)
(4) One can compare only things that are directly perceived.
(5) Only ideas can be directly perceived.
(6) Resemblance can obtain only between ideas. (3, 4, 5)
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As Ryan notes, this argument would show not just that two things having been compared
is “a necessary condition for knowing that the two things resemble, but that it is a
necessary condition for two things resembling at all.”xix
Although I have other reservations about this reconstruction, I shall confine
myself to one criticism.xx This is that a representationalist need not accept (2), because
she need not accept the mind-dependence of relations. Furthermore, despite the passages
that Ryan quotes from Locke, and other passages in the same vein in the Essay, it is far
from clear that Locke accepts such a view. There are of course metaphysical issues about
the status of relations, stemming from the fact that they are neither substances nor
(monadic) properties or Lockean “modes,” and Locke shows his own awareness of these
issues when he says such things as that “Relation [is] not contained in the real existence
of Things, but something extraneous, and superinduced” (Essay II.xxv.8). But it does not
follow from this that Locke was prepared to relegate relations to the dustbin of the mind.
After all, he tells us that “One single man may at once be concerned in, and sustain all
these following Relations, and many more, viz. Father, Brother, Son, Grandfather,
Father-in-Law, Son-in-Law, Husband, Friend, Enemy, Subject, General, Judge, Patron,
Client, Professor, European, English-man, Islander, Servant, Master, Possessor, Captain,
Superior, Inferior, Bigger, Older, Younger, Contemporary, Like, Unlike, etc. to an almost
infinite number…” (Essay II.xxv.7). I find it difficult to believe that Locke believed that
a man must await being compared by some mind with the appropriate correlative(s)
before actually bearing any of the above relations. Furthermore, Locke uses phrases that
imply the objectivity of relations, such as “perceives the Relation,” “overlooks … a
relation,” and “[cases where] the Relation is not always so easily taken notice of” (Essay
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II.xxv.2). Finally, he classifies both causality and identity as relations, and he surely did
not believe that impulses cause motion or that the sapling is identical with the grown oak
only if someone “compares” or “has compared” them. I think, then, that when Locke
talks of relations in terms of making comparisons, he means to say only that we come to
know of relations by comparing things, not that acts of comparison are constitutive of
relations. Perhaps one reason he uses language that suggests otherwise is that it seems
very difficult to give a non-circular definition of “relation” without alluding to some act
of comparing. But this does not entail that the things compared do not stand in various
relations independently of being compared. As for Ryan’s point that Berkeley may have
held that all relations essentially involve an act of mental comparison, it can carry no
weight against Locke, or more generally against representationalists, if they are not really
committed to that (dubious and rather idiosyncratic) doctrine.
5. The Significance of the Likeness Principle
What is the significance of Berkeley’s Likeness Principle, in light of my
reconstructions of his argument for it? Has Berkeley shown that representational theories
of perception are untenable?
Berkeley has shown, I believe, that one type of representational theory is
untenable. This is the familiar version, commonly but somewhat unfairly attributed to
Locke, according to which only ideas can be perceived, and the material things that these
ideas supposedly resemble are in principle unperceivable. I have already said that passage
B provides a knockdown objection to this form of representationalism. I now add that
Berkeley also provides a refutation of this version of representationalism in passage A,
because that version of the theory is committed to premises (2a) and (3) of the first
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reconstruction and to premises (B) and (C) of the second reconstruction. But I have
shown that those premises lead easily to LP, and consequently to the conclusion that
ideas cannot resemble material things. Insofar as Berkeley’s target was
representationalism of this sort, his arguments in Principles I section 8 are devastating.
It does not follow, however, that Berkeley provides a general refutation of
representationalism; on the contrary, he quite fails to do so. For representationalists do
not have to accept the “ideaistic” premises used in Berkeley’s arguments for LP; indeed,
it is doubtful that Locke, though be clearly held some form of representationalism, was
firmly committed to those premises. In this section, accordingly, I shall indicate how a
representationalist can formulate his position in such a way as to avoid Berkeley’s
refutation by the Likeness Principle. I shall not try to settle the question of whether
Locke’s own version of representationalism should be equated with the one Berkeley so
successfully attacks or with the one that I shall sketch, because I think that Locke is
simply ambiguous on this point, so that neither answer to this question would be wholly
correct. Further, the philosophically interesting question is whether any version of
representationalism can withstand Berkeley’s attack in section 8. I think that the answer
to that question is yes.
The key to formulating a version of representationalism that does not fall prey to
Berkeley’s Likeness Principle is to distinguish clearly between perception tout court and
immediate perception. A representationalist is of course committed to the view that we
immediately perceive only ideas. But, as previously noted, she is not thereby necessarily
committed to the view that we perceive only ideas. To see this more clearly, it is
necessary to determine the meaning(s) of the crucial term, “immediately perceive.” Now
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there is one sense of this term—a sense that can be found in Berkeley and other modern
philosophers as well--on which it is arguably true that we can immediately perceive only
ideas. This is an epistemological sense, which I define as follows:
D1: X is immediately perceivede = df X is perceived in such a way that its
existence and nature can be known solely on the basis of one’s present
perceptual experience.xxi
Given this definition, it can be shown, by appealing to hallucinations and dreams, that the
only possible objects of immediate perception are ideas. The definition, as it were,
“selects” ideas as the only possible objects of immediate perception: if such objects exist
at all, they can only be ideas.xxii But notice that there is no conflict at all between saying
that only ideas are immediately perceivede, and that material things are perceived. Upon
viewing an envelope from a certain angle, for example, I immediately perceivee (perceive
in such a way that I can know its existence solely on the basis of my present visual
experience) a rhomboidal, whitish patch, and I perceive (though not in such a way that I
can know its existence solely on the basis of my present visual experience) an envelope.
There is also another sense of “immediately perceived,” on which
representationalists, at least, are committed to saying that we immediately perceive only
ideas. This is what may be called the “no-intermediary sense,” and it can be defined
roughly as follows:
D2: X is immediately perceivedo = df X is perceived, and it is false that X
would be perceived only if some item that is not identical with X and that
is not a part of X were perceived.xxiii
21
Berkeley introduces this sense of the term early in the First Dialogue, and it also figures
prominently in his works on vision.xxiv But notice that saying that only ideas are
immediately perceivedo is perfectly compatible with saying that material things are
perceived: even if it be true that I do not perceive the envelope unless I immediately
perceiveo the rhomboidal patch, it does not follow that I do not perceive the envelope.
Thus, it is open to the representationalist to say that I perceive both the rhomboidal patch
and the envelope, though I perceive them in different ways. One might object that this
falsifies the phenomenological facts, because I do not then see two objects, but only one.
The representationalist may reply that admittedly, I do not see two objects separated in
space; indeed, the rhomboidal object that I see is not in physical space at all. Yet, she
may say, I can see the envelope only by also seeing the rhomboidal object. The
representationalist will want to add that (a) the envelope is the cause of my immediately
perceiving the rhomboidal patch, and that (b) the rhomboidal patch in some important
way (presumably involving resemblance) represents the envelope. I am not saying that
such an account of perception is correct: obviously much would have to be said to clarify
(a) and especially (b), and my own preference is for an adverbial view of perception that
does away with objects of immediate perception altogether. All I wish to claim is that a
version of representationalism that distinguishes between perception and immediate
perception eludes Berkeley’s objections in section 8. By this I do not mean that even if
LP were established, it would be ineffective against such a theory: LP obviously rules out
any resemblance between ideas and material things, regardless of whether only ideas are
perceived, or only ideas are immediately perceived.xxv My claim, rather, is that the
argument for LP becomes invalid when its premises are amended so as to accommodate
22
the perception/immediate perception distinction. So by building this distinction into her
theory, the representationalist can protect the theory from refutation by LP, since the
distinction deprives LP of the argumentative support that it requires.
To see this, let us see what happens when we modify the premises of the
reconstructed arguments for LP to accommodate the perception/immediate perception
distinction. The first reconstruction would have to be replaced by the following
argument:
(1a') All immediately perceived representations of sensible qualities are
things that can resemble only sensible qualities and ideas of sensible
qualities.
(2a') All immediately perceived representations of sensible
qualities and ideas of sensible qualities are ideas.xxvi
(3') All ideas of sense are immediately perceived representations of
sensible qualities.
(4') All ideas of sense are things that can resemble only sensible qualities
and ideas of sensible qualities. [from (1a') and (3')]
(5') All things that can resemble only immediately perceived
representations of sensible qualities and ideas of sensible qualities are
things that can resemble only ideas. [from (2a')]
(6) All ideas of sense are things that can resemble only ideas. [from (4')
and (5')]
But it is obvious that the inference from (4') and (5') to (6) is invalid.
The second reconstruction would have to be formulated as follows:
23
(A') Whatever is immediately perceivable can be like only
something perceivable.
(B') Whatever is immediately perceivable is an idea.
(C') Whatever is an idea is immediately perceivable.
(D) Whatever is an idea can be like only something perceivable.
[from (A') and (C')]
(E') Whatever can be like only something immediately perceivable
can be like only an idea. [from (B')]
(LP) Whatever is an idea can be like only an idea. [from (D) and (E')]
But again, it is obvious that the inference from (D) and (E') to (LP) is invalid.
However, Berkeley might here reply that even the more sophisticated form of
representationalism succumbs at least to the second reconstruction, provided that we
build into the argument a principle that he repeatedly insists upon in the Three Dialogues
Between Hylas and Philonous. This is what I call his Principle of Perceptual Immediacy
(PPI), which says that whatever is perceived by the senses is immediately perceived.xxvii
For then, letting “perceivable” mean “perceivable by the senses,” this principle implies
and is implied by:
(F) Whatever is perceivable is immediately perceivable.
But once (F) is added, the second reconstruction can be validly completed as
follows:
(G) Whatever can be like only something perceivable can be like
only something immediately perceivable. [from (F)]
(H) Whatever is an idea can be like only something immediately
24
perceivable. [from (D) and (G)]
(LP) Whatever is an idea can be like only an idea. [from (H) and
(E')]
Whether this attempt to refute more sophisticated forms of representationalism is
successful turns on whether, on either sense of immediate perception on which the
representationalist must agree that we immediately perceive only ideas (and thus accept
(B')), (PPI) is true. Those two senses are the epistemological one (“immediately
perceivede”) and the no-intermediary one (“immediately perceivedo”). Suppose then that
the term has its epistemological sense. Then PPI means
PPIe: Whatever is perceived by the senses is perceived in such a way that
its existence and nature can be known solely on the basis of a given
present perceptual experience.
But PPIe is false: when I look an envelope in my hands in good light, I cannot know that
it exists or is an envelope solely on the basis of my present perceptual experience, since I
could have the same experience in a hallucination or a dream. Yet, it does not follow that
I do not then perceive the envelope by sight (that I do not see it); rather, all that follows is
that I do not see it in the privileged epistemic sense of “immediately perceivede”. Thus, if
“immediately perceived” has the epistemological sense, then the representationalist can
safely reject premise (F) (“whatever is perceivable is immediately perceivable”).
Alternatively, suppose that the term has its “no-intermediary” sense. Then PPI means
PPIo: Whatever is perceived by the senses is perceived in such a way that
it is false that it is perceived only if some item that is not identical with it
and that is not a part of it is perceived.
25
But a careful representationalist will hold that PPIo is false: she will hold that whenever
one sees an envelope, one sees a colored patch that is not identical with the envelope or
any part of it, but that this is perfectly compatible with saying that one sees the envelope.
Thus, if “immediately perceived” has the no-intermediary sense, then again the
representationalist can safely reject premise (F).
Is there any sense of the term “immediately perceived” on which PPI is true? I
think that there is. In the First Dialogue, Berkeley has Hylas say, “in truth the senses
perceive nothing which they do not perceive immediately: for they make no inferences”
(W2 174-75). This suggests the following, psychological definition of “immediately
perceived”:
D3: X is immediately perceivedp = df X is perceived without (the
perceiver’s) performing any (conscious) inference.xxviii
I have included the word “conscious” parenthetically in the definition, because Berkeley
is not concerned here with what one might call “unconscious inference”--i.e. mental
processing or activity that occurs without our being aware of it. Rather, he is concerned
only with explicit, conscious reasoning: the sort of process that occurs when one follows
an argument step-by-step, or solves an equation, or figures out the likely consequences of
a proposed course of action. I suspect that for Berkeley, the definiens of “immediately
perceivedp” is extensionally equivalent to the definiens of “immediately perceivedo;” in
other words, that Berkeley believes that the things that answer to D3 are all and only the
things that answer to D2. His thought seems to be that since a thing is perceived
mediately (= not immediately) when it is perceived “not without [= with] the intervention
of others,” those other things must be items or data from which one draws an inference or
26
reasons to a conclusion that would not have been reached without the data. Thus I am
inclined to agree with Kenneth Winkler’s remark that “the subsequent exchanges show
clearly that both Hylas and Philonous take perception without intervention to be the same
as perception without inference.”xxixStill, these two concepts are different, and shortly we
will see that they are not really extensionally equivalent.
If we take “immediately perceived” in this psychological sense, then PPI means:
PPIp: Whatever is perceived by the senses is perceived without any
(conscious) inference on the perceiver’s part.
Now I think that PPIp is true. For the experience one has when one perceives something
by one’s senses—when one sees, touches, hears tastes, or smells something--is quite
unlike the experience of going through a process of reasoning or drawing an inference.
Sense perception has a certain psychological or phenomenological “immediacy” or
directness that marks it off from reasoning or inferring. Roderick M. Chisholm puts the
point this way:
It is sometimes said that to perceive something is to “make an inference”
or to “frame a hypothesis” . . . But surely no perceiver, on opening his
eyes in the morning, can be said to “infer” that he is surrounded by
familiar objects . . . If we do use the words “inference” and “hypothesis”
in this context, we cannot take them in the ordinary sense--in the sense in
which a physician, studying symptoms, may be said to “make an
inference” or “frame a hypothesis” about the disorders of his patients. Use
of the psychological terms “unconscious inference” and “interpretation,”
in this context, serves only to obscure the fact that perceiving is not an
27
inference, in the ordinary sense of the word “inference.”xxx
The truth of PPIp, however, does not salvage the argument for LP. For now the
representationalist may object there is no reason why she should accept premise (B')
(“Whatever is immediately perceivable is an idea”). For why should the
representationalist agree that the only things perceived without any conscious inference
are ideas? Representationalism does hold, to be sure, that the only things perceived
without any intermediaries—the only things immediately perceivedo—are ideas, but
from this it does not follow that material objects are not immediately perceivedp, and
thus not perceived by the senses. To return to my example, suppose that when I look at a
rectangular envelope from a certain angle, I can see it only if I see a rhomboidal patch of
color that is neither identical with nor part of the envelope, so that I do not immediately
perceiveo the envelope. It does not follow that to see the envelope I must infer its
existence from that of the rhomboidal patch. It is open to the representationalist to say
that I immediately perveiveo the rhomboidal patch and immediately perceivep the
(rectangular) envelope. Here again one might object that this falsifies the
phenomenological facts since I do not then see two objects but only one. But again the
representationalist may accommodate the phenomenological facts by admitting that I do
not see two objects separated in space, since the rhomboidal object that I see is not in
physical space at all. Yet, she may say, I can see the envelope only by also seeing this
rhomboidal object, but this does not mean that I must then infer the envelope’s presence
from the patch. Rather, I immediately perceivep the envelope, though I do not
immediately perceiveo the envelope: contrary to what Berkeley thought, “immediately
pereivedo” and “immediately perceivedp” are not extensionally equivalent. You may say
28
that these are odd ways of talking, and I would agree. My own view is that they are
misleading ways of reporting the fact that I see a rectangular envelope that looks
rhomboidal from a certain angle. But I can see no good reason why someone who holds a
representationalist theory of perception, and who reifies appearances in the way
representationalists characteristically do, should not talk in these ways.
In summary, I have argued for the following assessment of Berkeley’s Likeness
Principle. The argumentative support that this principle requires is available if one grants
that the only objects of sense perception are ideas; therefore the Likeness Principle
provides a refutation of the cruder forms of representationalism, which hold that we can
perceive ideas but that material things are in principle unperceivable. But the
argumentative support that the Likeness Principle requires is not available if one only
grants that the only immediate objects of perception are ideas; therefore the Likeness
Principle does not refute more sophisticated forms of representationalism, which hold
that we immediately perceive only ideas but also perceive (though we do not immediately
perceive) material things.
Georges Dicker
The College at Brockport
State University of New York
29
Notes
i
David M. Armstrong (ed.), Berkeley’s Philosophical Writings (New York: Macmillan,
1965), p. 17.
ii
Phillip D. Cummins, “Berkeley’s Likeness Principle,” p. 65. Journal of the History of
Philosophy 4 (1966), pp. 63-69. This article is reprinted in C. B. Martin and D. M.
Armstrong (eds.), Locke and Berkeley: A Collection of Critical Essays (Notre Dame:
University of Notre Dame Press, 1968), pp, 353-363, and in Walter Creery (ed.), George
Berkeley: Critical Assessments, Volume II (London and New York: Routledge, 1991),
pp. 359-366.
iii
George Pitcher, Berkeley (London, Henley and Boston: Routledge & Kegan Paul,
1977).
iv
Georges Dicker, “An Idea Can Be Like Nothing But An Idea,” History of Philosophy
Quarterly 2 (1985), pp. 39-52. Reprinted in Walter Creery (ed.), George Berkeley:
Critical Assessments, Volume III (London and New York: Routledge, 1991), pp. 162176.
v
Kenneth G. Winkler, Berkeley: An Interpretation (Oxford: Oxford University Press,
1989).
vi
Todd Ryan, “A New Account of Berkeley’s Likeness Principle,” British Journal for
the History of Philosophy, 14:4 (November 2006), pp. 561-580.
vii
Here and in the rest of this chapter, “section 8” refers to section 8 of Part I of
Berkeley’s Principles of Human Knowledge. For good evidence that section 8 contains
two different lines of argument, see Todd Ryan, “A New Account of Berkeley’s Likeness
Principle,” British Journal for the History of Philosophy, pp. 562-64. Ryan shows that the
30
two parts of section 8 are foreshadowed in two arguments Berkeley offers, and considers
as distinct arguments, in his Notebooks (Philosophical Commentaries).
viii
For brevity’s sake, here and below I use “A” and “B” to refer to the key claims made
in passages A and B.
ix
Passages where Locke seems to embrace this view include these:
SINCE the Mind, in all its Thoughts and Reasonings, hath no other
immediate Object but its own Ideas, which it alone does or can
contemplate, it is evident, that our Knowledge is only conversant
about them. (Essay IV.i.1)
ALL our Knowledge consisting, as I have said, in the view the
Mind has of its own Ideas ... (Essay IV.ii.1)
How shall the Mind, when it perceives nothing but its own Ideas,
know that they agree with Things themselves? (Essay IV.iv.3)
Notice how, in the first passage, Locke moves from saying that only ideas are
immediately perceived, to saying that only ideas are perceived: we can
“contemplate” only ideas.
x
Edwin B. Allaire, “Berkeley’s Idealism Revisited,” p. 203. In Colin M. Turbayne (ed.),
Berkeley: Critical and Interpretive Essays (Minneapolis: University of Minnesota Press,
1982), pp. 197-206.
xi
Phillip D. Cummins, “Berkeley’s Likeness Principle,” p. 65. Journal of the History of
Philosophy 4 (1966), pp. 63-69. This article is reprinted in C. B. Martin and D. M.
Armstrong (eds.), Locke and Berkeley: A Collection of Critical Essays (Notre Dame:
University of Notre Dame Press, 1968), pp, 353-363, and in Walter Creery (ed.), George
31
Berkeley: Critical Assessments, Volume II (London and New York: Routledge, 1991),
pp. 359-366.
xii
George Pitcher, Berkeley (London, Henley and Boston: Routledge & Kegan Paul,
1977), p. 116. It is not so clear that a picture of a piano is like a piano in a “perfectly
straightforward” way. The picture is flat but the piano is not (at least not in the same
sense of “flat”!), the piano can make music but the picture cannot, and so on. There are
complex issues about the nature of representation beneath the surface here. I shall ignore
such issues in what follows.
xiii
xiv
xv
This was pointed out to me by Daisy Radner.
Ryan,“ A New Account of Berkeley’s Likeness Principle,” p. 565.
Ryan, Ibid., p. 565. Ryan’s quotation is from Pitcher, Berkeley, p. 117.
xvi
In formulating these premises, I have deliberately followed Berkeley’s frequent
practice of omitting the qualification, “immediately,” which, it might be said, ought to
precede “perceivable.” The implications of reintroducing this qualification will be taken
up in the next section.
xvii
Ryan, “A New Account of Berkeley’s Likeness Principle,” p. 575.
xviii
xix
xx
Ibid.
Ibid., p. 576.
My other reservation concerns premise (4), which, in light of what I shall say about
immediate (“direct”) perception in the next section, seems to me to be untrue.
xxi
I introduced this definition in Perceptual Knowledge: An Analytical and Historical
Study (Dordrecht: Reidel, 1980), p. 56 (though there I used “a given perceptual
experience” instead of “one’s present perceptual experience”). I have discussed the
32
definition, and argued that the sense of “immediately perceived” that it captures can be
found in Berkeley, in a number of articles, most recently in “Berkeley on Immediate
Perception: Once More Unto the Breach,” Philosophical Quarterly 56: 225 (October
2006), pp. 517-535, especially section III. My other discussions of it can be found in
“The Concept of Immediate Perception in Berkeley’s Immaterialism,” in C. M. Turbayne
(ed.), Berkeley: Critical and Interpretive Essays, (Minneapolis: University of Minnesota
Press: 1982), pp. 48-66, and in “Berkeley on the Immediate Perception of Objects,” in
Phillip D. Cummins and Guenter Zoeller (eds.), Minds, Ideas, and Objects: Essays in the
Theory of Representation in Modern Philosophy, North American Kant Society Studies
in Philosophy, Volume 2, (Atascadero: Ridgeview Publishing Company, 1992), pp. 201213.
xxii
There is a full-scale defense of this claim in Georges Dicker, Perceptual Knowledge:
An Analytical and Historical Study (Dordrecht: Reidel, 1980), Chapters 3 and 4 (though
there the term “sense-data” is used rather than “ideas”).
xxiii
For a highly detailed and refined discussion of this kind of definition of immediate
perception, see George Pappas, Berkeley’s Thought (Ithaca: Cornell University Press,
2000), pp. 148-160.
xxiv
For evidence that Berkeley uses the term in his sense, see Pappas, Berkeley’s
Thought, pp. 148-151.
xxv
I am indebted to Deborah Modrak and Paul Weirich for clarification on this point.
xxvi
The phrase “immediately perceived representations of sensible qualities and ideas of
sensible qualities” is not a mere redundancy, because “immediately perceived
33
representations of sensible qualities” can refer to ideas had in perception and “ideas of
sensible qualities” can refer to ideas had in imagination and in memory.
xxvii
It is important to note that this principle is no mere tautology, saying that whatever
is perceived by sense is perceived by sense, or that whatever is immediately perceived is
immediately perceived, or the like. Rather, the subject term “perceived by sense” and the
predicate term “immediately perceived” have different meanings. The former refers to
sense-perception, the latter needs to be defined, and the truth of the principle depends on
how it is defined. Passages where Berkeley affirms this principle in Three Dialogues
Between Hylas and Philonous include at least W2 174-75, 183, 194-95, 203, 204, 205,
215. For discussion of these passages, see my “Berkeley on Immediate Perception: Once
More Unto the Breach,” pp. 530-531. In that article, pp. 531-535, I also argue that
Berkeley ultimately accepts a qualified version of PPI that allows for what he calls
“suggestion.” Although I shall not argue the point here, I believe that substituting the
qualified version of PPI into the reconstruction I am about to offer would not change the
evaluation of it that I shall give.
xxviii
I defend view that Berkeley uses “immediately perceive” in this sense in the papers
cited in note 16,
xxix
xxx
Kenneth G. Winkler, Berkeley: An Interpretation, p. 150.
Roderick M. Chisholm, Perceiving: A Philosophical Study (Ithaca: Cornell University
Press, 1957), pp. 158-159.