The Argument from Ignorance against Truth-conditional Semantics
Paul Saka
University of Houston
www.uh.edu/~psaka
According to epistemic brands of truth-conditional semantics, which dominate the
philosophy of language, to know the meaning of a statement is to know its truthconditions or the set of possible worlds in which it would be true.1 Against this view,
henceforth "truth-conditionalism", I shall argue that in many cases:
(a)
We know, for a given statement P, the meaning of P.
(b)
We do not know the truth-conditions of P.
(c)
Therefore knowledge of meaning ≠ knowledge of truth-conditions.
I begin by citing cases where we know the meaning of a statement yet do not know its
truth-conditions, and afterwards I respond to some possible objections.
Cases. To begin with, consider the truth-conditions for ethnic slurs as in:
(1)
Hitler was a kraut.
According to the Simple Conjunction Theory, (1) is equivalent to "Hitler was German,
and Germans are despicable", which is false. According to the Indexical Conjunction
Theory, (1) is equivalent to "Hitler was German, and I despise Germans"; its truth-value
varies from speaker to speaker. According to the Bracket Theory, pejoration is a
parenthetical side feature, and (1) is truth-conditionally equivalent to just "Hitler was
German"; it is true. According to the Stereotype Theory, (1) is equivalent to "Hitler meets
the negative stereotype of Germans", which is also true, though it differs from the
1
The first explicit account of truth-conditionalism appears to be Wittgenstein
1921:4.024; especially influential accounts include Davidson 1970:56 and Lewis 1972:;
textbook accounts include Dowty et al. 1981:4, Larson and Segal 1995, Lycan 1999:131,
and Chierchia & McConnell-Ginet 2000:73.
Bracket Theory in treating "Einstein is a kraut" as false. According to Disquotational
Semantics, (1) is true if and only if Hitler was a kraut, which is hardly informative; even
given complete knowledge of the world, the truth-value of (1) remains unknown.
According to various Non-proposition Theories, (1) either rests on a false presupposition
or functions expressively; it is neither true nor false.2
The existence of such disagreement means that no one really knows what the
truth-conditions of (1) are. Even if someone happened to have the right idea, that
wouldn't count as knowledge. For example, just suppose that the Conjunction theory
happens to get the right truth-conditions for (1). Then Conjunction theorists would seem
to be lucky, not particularly justified. They could say "I knew it all along", and they could
think that they had sound reasons to support the theory, but all the rival theorists can do
the same. Of course Conjunction theorists could add that they were smarter than everyone
else, which might even be true; but unless they had objective evidence for this, and also
reason to think that extra intelligence is effective at getting at the right theory of
vagueness, they would have insufficient justification because justification has a social
dimension: one's awareness of controversy serves as a defeasible defeater to one's own
knowledge claims. Even if we granted that Conjunction theorists know or grasp the truthconditions of (1), it would then follow that rival theorists do not know or grasp it. Yet
they all understand English; therefore knowing the language does not entail knowing or
grasping the truth-conditions.
2
The Conjunction and Bracket Theories are offered by Stenner 1981 and also Blackburn
1984:148, Non-proposition Theories by Grim 1981, Taylor 1981, and xxxx 2003, and the
Stereotype Theory by Alistair Isaac, Steven Todd, and Evan Dukovsky; for extended
treatment, see xxxx 2003.
2
The variety of theoretical positions demonstrates that no one knows the truthconditions of "Hitler was a kraut". Not only that, the truth-conditions are so unspecified
that we could stipulate any precisely defined world, and we would still not know its truthvalue. We do not know any of its truth-conditions. There is no conceivable condition
under which (1) counts as categorically true according to all theories (for the Indexical
Theory treats truth as relative while some Non-proposition Theories treat truth
eliminatively), there is no condition under which (1) counts as categorically false by all,
there is no condition under which (1) counts as relatively true by all theories, and so
forth. This means that not a single truth-condition is known.
This is not a case of borderline fuzziness; this is a case where the concept at its
center is inscrutable, if concepts are truth-theoretic categories. But of course the concept
or meaning of "kraut" is not inscrutable; we understand someone who uses the word, we
understand who is being referred to, we understand what the speaker's attitude toward the
referent is, we understand not only what the speaker's feelings are but something about
the discourse's level of civility (or lack thereof). We know everything there is to know
about the conventions behind the word. We know its meaning, though we do not know its
contribution to truth-conditions.
Truth-conditionalists may reply that pejoratives are recherché. They may say that
pejoratives represent a marginal aspect of language that can fairly be ignored by semantic
theory. This move, however, makes multiple mistakes. First, it is a mistake to dismiss
recalcitrant data or logical difficulties by equating either rarity or small size with
inconsequentiality. Observational discrepancies at the sixth decimal place prove that
Einstein's theory is superior to Newton's, and Russell's single paradoxical sentence proves
that naïve set theory is inconsistent. There is no such thing as a "little" inconsistency; one
counter-example fells a theory.
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Second, it is a mistake to think of pejoratives as aberrations. Elsewhere I relate
pejoratives proper to connotation more generally, which is ubiquitous. It is not just racist
and sexist slurs, but any expression having point-of-view content, that raises questions
about truth-conditions.
Quite aside from connotation, the problem of identifying truth-conditions emerges
for almost every kind of construction. It famously arises for definite descriptions
(Russellians hold that under actual conditions "the king of France is bald" is false,
Strawsonians that it is neither true nor false). The problem arises for so-called category
mistakes (category errorists regard "rectangularity drinks procrastination" as obviously
neither true nor false, others regard it as obviously false). The problem arises for nondeclarative sentences and for attitude contents other than belief (imperatives are analyzed
as simple futures by Chomsky's standard theory, as performatives by generative
semanticists, as veiled threats by Bohnert 1945 and others, as sequences of declaratives
by Davidson 1979…). The problem notoriously arises for belief ascriptions, for
subjunctive conditionals and causal statements and probability statements, and for
figurative language. Absolutists like Unger 1975 deny the strict truth of statements like
"my desk is flat"; while others, relativizing to loose standards, insist on their complete
truth. In the realm of moral and esthetic philosophy, normative judgments are interpreted
by Kantians as consistency-claims, by utilitarians as consequence-claims, by Stevenson
1944 as exclamations, by Hare 1952 as prescriptions, by Phillips 1998 as indexical
claims,… Indeed, the whole history of philosophy starting with Socrates can be read as
primarily the history of trying to find truth-conditions. It is a history that, fascinating and
valuable though it is, has yet to yield knowledge.
To all appearances, then, knowledge of meaning rarely if ever correlates with
knowledge of truth-conditions: you can have the former without the latter. To this I have
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time to discuss three possible replies. The Double Ignorance Defense admits that we lack
knowledge of truth-conditions, but insists that we also lack knowledge of meaning. The
Double Knowledge Defense admits that we know the meanings of the sentences we utter,
but insists that we actually know the truth-conditions. The Dialect Defense denies that
there exists any collective "we" to which the question of knowledge applies; a given
individual S understands a sentence P in one idiolect, in which case S knows P's truthconditions, but does not understand the homophonous P* from a different idiolect, in
which case S does not know P*'s truth-conditions.
These positions will be described and discarded in order.
The Double Ignorance Defense. The notion that we do not understand a sentence
P of the sort discussed, or know its meaning, strikes me as absurd. First off, we know the
conventions of use for P as well as we know the conventions of use for any construction.
If we do not know the meaning of P then we do not know the meaning of anything, which
is absurd. Second, we know the conventions of use for P as well as anyone does. If we do
not know the meaning of P then no one does, and if no one knows the meaning of P then
P is not English or part of any language whatsoever. Third, our knowledge of the
meaning of P is supposed to explain our linguistic behavior relating to P. If we didn't
understand P then we would never utter P or respond to others' utterances of it in the way
we do.
In fact, the Double Ignorance Defense appears to come down to an exercise in bad
faith. The Double Ignorance Defense correlates knowledge of meaning with knowledge
of truth-conditions, and all along it quietly holds that knowledge of meaning never exists.
"To know the meaning of a statement is to know its truth-conditions" might be materially
valid but only because it's vacuous; we could, with equal justice, maintain that to know
sentence meanings is to know tooth fairies.
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The Double Knowledge Defense. Truth-conditionalists might maintain that we
really do know relevant truth-conditions, it's just that we cannot articulate them, we have
no conscious access to them, and we do not all know that we know them. Knowledge of
truth-conditions exists but is not explicitly propositional, it is implicit, tacit, or takes the
the form of know-how.
This last suggestion, if taken literally, is ridiculous. The object of know-how is an
action: one knows how to ride a bike, one knows how to cook a soufflé, one knows how to
speak Navaho (or not, as the case may be). In contrast, knowledge of truth-conditions does
not take an action as its object; it takes a kind of condition or a set of conditions or a pairing
of sentences with conditions. Knowledge of truth-conditions is not know-how.
Yet knowledge of truth-conditions may be related to know-how. Cognitive
scientists often ascribe propositional knowledge in order to describe or explain a subject's
motor skills, grammatical competence, visual recognition abilities, and so forth. In doing
so they do not necessarily claim that S possesses a language (which many regard as
necessary for the possession of any propositional knowledge) or that S's knowledge is
either linguistically encoded or accessible to S's consciousness. They are merely claiming
a virtual equivalence: that, in principle, one possessing the knowledge in question would
be able to exhibit S's abilities. For instance, in describing/explaining the particular
inferences that S makes, we might attribute to S the schematic knowledge that φ, φ→ψ |ψ even if S lacks explicit knowledge of Greek letters or the concept of metavariables.
While this "virtual equivalence" view poses difficulties that I must pass over here,
I will grant it, both because I find it promising in its own right and because I want to
grant as much as I can for the sake of argument. Nonetheless, it misses the point of my
Argument from Ignorance. I never denied to speakers explicit knowledge of Tarskian
truth-theoretic or Montagovian possible-world formulas (which would be true but beside
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the point). I deny that speakers are even virtually equivalent to any mechanism that did
have such knowledge. Speakers do not possess the appropriate competence -- for
instance, to judge whether pejoratives are ever true or to draw all and only valid
inferences from (1) -- that would justify ascribing truth-conditional knowledge to them.
Ascribing truth-conditional knowledge to someone who does not know the truth-value of
a statement under a particular condition, even when asked to think about it, is like
ascribing the knowledge that φ, φ→ψ |- ψ to someone who cannot decide whether P,
P→Q |- Q in a particular case.
It may be said that pragmatic factors cloud the semantic facts. This sort of
confusion is illustrated by careless speakers who read (2) as stating (3), though it does no
such thing.
(2)
I have a wife.
(3)
I have only one wife.
Pragmatic inferences, be they based on Gricean maxims or more generally on
expectations regarding the way the real world works, do distort perceived semantic
content.
It is essential to the Gricean program, however, that semantic content is normally
identifiable. For if it weren't, there would be no way to tell whether Gricean principles
can carry us from the "real" posited semantic content to the experienced pragmatic
content; indeed, there would never have been any impulse in the first place to postulate a
layer of real content together with machinery for explaining apparent content. Yet truthconditions, as I have stressed, are normally not identifiable.
What's more, there are methods for blowing pragmatic fog away from truthconditional content, for instance the cancelability test (Sadock 1978). I can, without
contradiction, assert (2) while canceling its implicature (3):
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(4)
I have a wife, but not only one mind you.
This establishes, what sensitive speakers already knew, that in saying (2) one does not
thereby say (3).
Now one could make up pragmatic stories as to why pejoratives, category
mistakes, subjunctives, belief ascriptions, ad infinitum all have mysterious or misleading
truth-conditions. For instance, one could hold that imperatives don't seem to have truthconditions because being true or false is not their point, and speakers normally
concentrate on the point of a communication rather than on what is literally said.
However, if this is the story then it should allow for a twist ending, just as (4) did and just
as (5) does.
(5)
Could you tell me the time? I'm not asking you "what time is it?", I'm asking
whether you have a certain ability.
(6)
Eat your spinach! I don't mean that as an order, or not solely as an order, I mean it
as something true or false.
Although (5) is unusual, it makes perfect sense. In contrast (6) is bewildering. Is the
speaker predicting that you will eat your spinach, or observing that you are now eating
your spinach, or what? Neither established tests for pragmatic effects, nor sensitivity as
measured by agreement among language experts who have reflected on non-declaratives
(be they in literature, linguistics, philosophy, or law), hints that grasping nondeclaratives, deep down, is constituted by grasping truth-conditions.
I conclude that the missing truth-conditions in question are not veiled by
implicature or any other known pragmatic effect, and when speakers disagree about truthconditions it is not because of obtuseness. Rather, knowledge of truth-conditions does not
exist, at least not attached to sentence types or tokens.
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The Dialect Defense. Because theorists disagree, it might be suggested that each
theorist has true (and justified) access to the truth-conditions in his or her own idiolect.
Although they all belong to a community that can loosely be called anglophone, the
members in it assign meanings (truth-conditions) to sentences in divergent ways. As a
result the Simple Conjunction Theory of pejoratives correctly describes one variety of
English, the Indexical Conjunction Theory correctly describes another, the Bracket and
Stereotype Theories yet others...
It's true of course that idiolects do differ. Otherwise language would never change
over generations. But this fact does not save truth-conditionalism. On the one hand, if
competing theories of the pejorative are all correct, each one for a different dialect, then
in some dialects meaning would be non-truth-conditional. For certain Non-Proposition
Theories are non-truth-conditional. And if meaning is non-truth-conditional in some
languages then truth-conditions, instead of being the essence of language, are at best an
accident of particular languages.
On the other hand, if any seriously proposed theory of pejoratives is incorrect then
the problem remains: whoever subscribes to an incorrect theory does not know the
relevant truth-conditions, yet does presumably know the relevant meaning. What's more,
one and the same individual will sometimes propose incompatible truth-conditions for a
given statement. Blackburn and Stenner, for instance, both do this, and they openly
acknowledge that they see no way to identify the "real" truth-conditions of pejoratives.
Finally, there is evidence that at least some of the proposed truth-conditions of
pejoratives are just wrong (xxxx 2003). But no one can get the truth-conditions wrong
unless either (a) they do not know the relevant meaning, or (b) knowing the meaning is
not the same as knowing truth-conditions.
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It's worth noting that the Dialect Defense stands in a certain tension to the overall
truth-conditionalist position. For the acceptability of truth-conditionalism depends, at
least indirectly and in part, on the rejection of its chief rival, conceptual role semantics
(CRS). Yet the truth-conditionalists' favorite argument against CRS is that CRS admits
too much dialectal variation. If CRS were correct, so the argument goes, then every
speaker would command a distinct idiolect, in which case, strictly speaking, there would
be no such thing as a common language, hence no communication, which is absurd. For
my part, I see nothing absurd in denying the existence of "the" English language, unless
English be understood as an abstraction or collection which no one individual speaks.
However, I am not here to defend CRS, only to point out a flaw in truth-conditional
semantics. truth-conditional semantics cannot consistently criticize CRS for entailing
pervasive idiolect variation while at the same time invoking pervasive idiolect variation
as a reply to the Argument from Ignorance.
Much more needs to be said. As I am out of time, however, I will leave off by just
mentioning some alternatives to truth-conditional semantics. One, conceptual role
semantics, explains linguistic behavior in terms of syntactically defined language moves.
The other, cognitive semantics, understands linguistic competence in terms of prototypes,
schemas, frames, idealized cognitive models, embodiment, metaphor, and the structure of
the mind rather than the structure of the world. CRS, which fits easily into the physicalist
program, and cognitive semantics, a form of psychologism, are quite possibly compatible
with each other. Either one would provide easy entry into naturalized philosophy of
content.
References
Blackburn, Simon (1984) Spreading the word, Oxford.
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Bohnert, Herbert (1945) "The semiotic status of commands", Philosophy of Science
12:302-15.
Chierchia, Gennaro & Sally McConnell-Ginet (2000) Meaning and grammar, 2/e, MIT.
Davidson, Donald (1970) "Semantics for natural language", reprinted in (1984).
---- (1979) "Moods and performances", reprinted in 1984.
---- (1984) Inquiries into truth and interpretation, Harvard.
Dowty, David, Robert Wall, & Stanley Peters (1981) An introduction to Montague
semantics, Dordrecht: Reidel.
Grim, Patrick (1981) "A note on the ethics of theories of truth", in Vetterling-Braggin.
Hare, RM (1952) The language of morals, Oxford.
Larson, Richard & Gabriel Segal (1995) Knowledge of meaning, MIT.
Lewis, David (1972) "General semantics", in Semantics of Natural Language (ed.
Davidson and Harman), Dordrecht: Reidel.
Lycan, William (1999) Philosophy of language, Routledge.
Phillips, David (1998) "The middle ground in moral semantics", American Philosophical
Quarterly.
Sadock, Jerrold (1978) "On testing for conversational implicature", Syntax and Semantics 9.
Stevenson, CL (1944) Ethics and language, Yale.
Taylor, Kriste (1981) "Reference and truth", in Vetterling-Braggin.
Unger, Peter (1975) Ignorance, Oxford.
Vetterling-Braggin, Mary, ed. (1981) Sexist language: a modern philosophical analysis,
Totowa NJ: Littlefield & Adams.
Wittgenstein, Ludwig (1921) Tractatus logico-philosophicus (tr Pears & McGuinness),
Routledge, 1961.
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