American Philosophical Quarterly

Volume 44, Number 2, April 2007

157

THE ARGUMENT FROM IGNORANCE AGAINST

TRUTH-CONDITIONAL SEMANTICS

Paul Saka

According to mainstream truth-condi-

tional semantics, to know the meaning of

a sentence is to know its truth-conditions.

Against this thesis—epistemic truth-condi-

tionalism or TC semantics—the Argument

from Ignorance holds that, in many cases, for

a given sentence or statement P:

(a) We know the meaning of P.

(b) We do not know the truth-conditions of

P.

(c) Therefore knowledge of meaning ≠

knowledge of truth-conditions.

One reason for holding (b) is that virtually

every statement is vague (section 1). Objec-

tions to the argument, for instance appeals to

tacit knowledge, are considered and rejected

in subsequent sections.

To be clear, the truth-condition of a sen-

tence (or declarative utterance) P is any real,

possible, or imagined condition under which

P is, or would be, true; the total truth-condi-

tions of P, or its truth-conditions simpliciter,

are all those conditions under which P is true;

and the partial truth-conditions of P are some

of the conditions under which P is true.1 As-

suming bivalence, the total truth-conditions

of P fi x the falsehood conditions as well.

Because conditions can be understood as sets

of possible worlds, the truth-conditions of a

statement can be understood as the charac-

teristic function from each possible state or

possible world to either T or F, while partial

conditions can be understood as functions

from select possible worlds to T or F.2

To know the truth-conditions of a statement

is to know the corresponding function from

world to truth-value. Knowledge of a func-

tion f requires knowing f either verbally or

practically. To know f verbally is to know a

true description of f, but this kind of knowl-

edge is not at issue. Speakers are notoriously

bad at formulating necessary and suffi cient

conditions. The kind of knowledge at issue is

practical, whereby to know f is to know, for

each value x that one considers, the value of

f(x), in which case knowledge of truth-condi-

tions plus relevant world knowledge should

produce knowledge of truth-value. This way

of understanding knowledge of truth-condi-

tions is explicit in the literature:

If someone knows the meaning of a sentence

and is omniscient regarding physical facts (that

is, is omniscient about all the non-semantic/

non-intentional facts), then he knows whether

the sentence is true. (Lepore 1994: p. 197)

If you know a sentence’s meaning and you are

omniscient as regards [non-linguistic] fact, then

you know the sentence’s truth-value. (Lycan

2004: §2)

158 / AMERICAN PHILOSOPHICAL QUARTERLY

Some, indeed, go so far as to sound like the

verifi cationist that they are not:

The semantic competence of a native speaker

is nothing more nor less than his ability, when

presented with a sentence and a situation, to tell

whether the sentence, in that situation, is true

or false. (Cresswell 1978: p. 10; reaffi rmed in

Cresswell 1994: p. 142)

[Linguistic competence] must be based on a

capacity to tell whether a sentence is true or

false in a given situation where the relevant facts

are available. (Chierchia and McConnell-Ginet

2000: p. 101)

Of course mere presence in a situation,

where the facts are available, does not give

one knowledge of the facts. But where

knowledge of fact does obtain, knowledge

of truth-conditions should yield knowledge

of truth-value.

I. Vagueness

Submitted for your consideration, exhibit

number one:

(1) The Queen of England is sitting on a

chair.

Normal speakers of English know the mean-

ing of (1), they understand it perfectly well.

But does anyone know the conditions under

which (1) would be true; does anyone know,

given an arbitrary possible world, whether (1)

be true or no? Would (1) be true if the Queen

were sitting on a stool with back support? In

a bean bag? In a bucket seat in a car? On a

tree stump in the wilderness, which she will

never see again? On a tree stump next to her

cabin, where she regularly relaxes? On the

futuristic furniture in Woody Allen’s Sleeper?

Slumped on a chair, resting on hip instead of

thighs and buttocks?

According to the epistemic theory of vague-

ness, vague statements are determinately true

or determinately false, but no one knows

which (e.g., Cargile 1969; Sorensen 1988,

2001; Williamson 1994). Furthermore, one

can remain ignorant even while knowing the

relevant conditions of the world, for instance

even if one had an exact description of the

physical object being sat upon, its past his-

tory of use, the intentions of its users toward

it, and so on. But if speakers are ignorant of

truth-value while having knowledge of real-

world conditions then speakers are ignorant

of at least some truth-conditions. Since we

understand (1), yet do not know its truth-

conditions, epistemological brands of truth-

conditionalism appear to be untenable.

It looks like epistemic theorists of vague-

ness, who are otherwise uber-realists, may

actually be committed to rejecting epistemic

truth-conditionalism. However, the epistemic

theory of vagueness is controversial, and its

appeal to ignorance does not make up the

Argument from Ignorance. The latter relies,

rather, on the fact that there is a welter of

mutually incompatible theories of vagueness,

which undermines any claim to knowing

which one is correct; it is this ignorance that

contradicts truth-conditionalism.

Against the epistemic theory of vagueness

there are numerous theories that call for giv-

ing up classical logic. Proposals include in-

tuitionism (Putnam 1983); three-valued logic

(e.g., Hallden 1949, Koerner 1966); truth-

functional continuum logic, which holds that

every statement has a determinate truth-value,

or determinate interval of values, ranging

from 0 to 1 (e.g., Goguen 1969, Machina

1976); non-truth-functional continuum

logic (e.g., Edgington 1995); and what may

be called profusion logic, which stipulates

a large but fi nite number of truth-values to

represent every degree of discriminability

(Morgan and Pelletier 1977). Others hold

that vague statements can be both true and

false (Black 1937, Priest 2006) or neither true

nor false (e.g., Mehlberg 1958, Fine 1975,

McGee 1992, Keefe 2000). Assuming that

these proposals are sincere, their advocates

will render divergent practical judgments in

borderline cases.

THE ARGUMENT AGAINST TRUTH-CONDITIONAL SEMANTICS / 159

The existence of such disagreement means

that no one really knows what the truth-

conditions of (1) are. Even if someone does

have the right idea, that would not count as

knowledge. For example, just suppose that

Kit Fine’s supervaluation theory happens to

get the right truth-conditions for (1). Then

Fine would seem to be lucky, not particularly

justifi ed. Fine could say “I knew it all along,”

and he could think that he had sound reasons

to support his theory, but all of his mistaken

peers can do the same. Of course Fine could

add that he was smarter than everyone else,

which might even be true; but unless Fine had

objective evidence for this, and also reason

to think that extra intelligence is effective at

getting at the right theory of vagueness, Fine

would have insuffi cient justifi cation for claim-

ing to have knowledge, for justifi cation has a

social dimension: the existence of controversy,

insofar as it provides relevant alternatives,

undercuts the validity of knowledge claims.

The formulation “to know the meaning of

P is to know that P is true iff P” is convenient

because the verb “know” easily takes as object

both that-clauses and noun phrases. At the same

time it’s fraught with epistemological baggage

that is perhaps better left behind. Indeed, the TC

slogan is often formulated in terms of grasp-

ing instead of knowledge. In this case, where

justifi cation and warrant are not at issue, it is

possible that someone—if not Kit Fine then

one of his rivals—really does have P’s correct

truth-conditions in mind. Even so, the problem

is that not enough grasping exists. For suppos-

ing Kit Fine to grasp the truth-conditions of (1),

it would then follow that rival theorists do not grasp it. Yet they all understand English; there-

fore understanding the language does not entail

knowing or grasping its truth-conditions.

Truth-conditionalists may respond by retract-

ing total truth-conditionalism, the thesis at play

so far, in favor of partial truth-conditionalism.

The idea is that to know the meaning of a state-

ment is to know some of the conditions under

which it is true or false, and to be undecided on

the rest. The claim, then, is that vague terms do

not really threaten TC semantics as it is intended

to be understood, or as it most plausibly is.

This move, however, is unconvincing. First,

appeal to partial predicates hardly solves the

problem of vagueness, given the penumbra

phenomena of higher-order vagueness: not

only do predicates F and non-F lack a sharp

line of demarcation, thus creating an interval

I of indefi niteness between them, so too there

is a border dispute between F and I creating an

interval I’, and so on. Second, partially defi ned

predicates appear to call for either a three-val-

ued or supervalued logic of vagueness, each

of which is accepted by only a small fraction

of semanticists. Third, profi les of judgments,

ranging from “defi nitely true” to “defi nitely

false,” are always unstable, both across speak-

ers and even intra-subjectively. Fourth, the

appeal to partial knowledge is not even ini-

tially plausible in the case of other linguistic

phenomena (Saka 2007: chap. 2.1.2).

Weatherson (2005) offers an exciting new

account of higher-order vagueness that is

modeled on structures other than linear or-

ders. Its future remains to be seen. For now,

the fact that we cannot agree on the right logic

establishes that, because of vagueness, we do

not know so much as the basic contours of

truth-conditions.

Incidentally, ordinary indexicality and

context-effects are not at issue, and so dis-

tinguishing among sentences, statements, and

utterances does not matter for present pur-

poses. Granted, focusing on particular utter-

ances of (1), made by real speakers at specifi c

times, may yield defi nite truth-values—utter-

ances made during the reign of Elizabeth II

while she is seated for dinner are normally

true, utterances made while she sleeps supine

are false—but the existence of defi nite truth-value does not negate the existence of vague truth-conditions. Knowing that an utterance

of (1) is true under given circumstances does

not tell us how far those circumstances can

change before we end with falsehood.

160 / AMERICAN PHILOSOPHICAL QUARTERLY

II. The Controversy Principle

It is suffi cient for the Argument from Ig-

norance that not everyone who knows the

meaning of (1) knows its truth-conditions.

More dramatically though, no one knows the

truth-conditions of (1). This latter claim rests

on the following Controversy Principle:

(CP) If controversy regarding proposition P

reigns in population S then, ceteris pa-

ribus, no individual in S knows whether

P be true.

CP is defeasible. Imagine that population S

is divided into two sides S1 and S

2, that (the

members of) S1 accept P, and that S

2 rejects

P. Then so far as CP is concerned, S1 may

genuinely know that P in any of the following

cases: where S1 happens to be positioned so

as to perceive that P while S2 is not; where S

1

happens to be aware of a good argument for

P while S2 is not; where S

1 happens to have

escaped indoctrination while the members

of S2, as uncritical children, were drilled in

catechism; or where S1 has nothing to gain

or lose in judging P while S2 is biased. In

the absence of such defeaters, however, the

presence of controversy entails that ignorance

prevails, or at least evinces it.

Controversy requires more than simple

disagreement. If side S1 consists of a single

subject while S2 includes everyone else then

there is disagreement without controversy. In

this kind of case, even if a specifi c defeater

cannot be found for explaining S1’s belief, it

might be reasonable to treat S1’s cognitions

as prima facie suspect, as mere noise in the

community that makes up the collective

epistemic system, or as outside of the com-

munity altogether (“beyond the pale”). But

the more an orthodox belief loses adherents,

due either to the rise of one rival or to a grow-

ing profusion of rivals, and the more that

the intra-community diversity of opinion is

recognized as a problem, then the more it is

that disagreement morphs into controversy.

Because controversy motivates partisan ef-

forts to change other minds, continued con-

troversy means that efforts at inter-subjective

intellectual justifi cation are unavailing, and

thus that knowledge does not yet exist.

Now CP, so understood, applies to the is-

sue of vagueness. First, disagreement among

vagueness theorists cannot be ascribed to vary-

ing perceptual experiences: all speakers, more

or less, can hear linguistic utterances and see

the contexts that they occur in with suffi cient

comparability. Second, disagreement cannot

be pinned on differences in bias: the fact that

theorists may be biased in favor of their own

work applies equally to all available theories,

and the fact that they may be biased in favor

of their mentors’ work does not seem to ap-

ply to any of them (for instance, Priest had no

personal stake in sustaining or developing the

work of Black). Third, disagreement does not

stem from differences in prejudice or knee-

jerk habits: it is not as if French schools train

their children to think of vagueness in terms

of three-valued logic while German schools

train otherwise. Fourth, disagreement cannot

be ascribed to variable theoretical knowledge:

partisans in the vagueness debates are scholars

who know the literature; supervaluationists,

intuitionists, epistemicists, and so forth are all

quite aware of their competitors’ positions and

arguments. Indeed, it is because scholars tend

to be so self-consciously aware of alternative

theories, and of the problem and importance of

choosing among them, that disagreement re-

garding vagueness rises to the level of genuine

controversy. And it is because the controversy

is so massive, implicating a large fraction

of the philosophical community as primary

researchers and as spectator bench-referees,

that it is plausible to say that available justi-

fi cations have been carefully inspected and

found inter-subjectively wanting.

The Controversy Principle follows, though

only part way, those many historiographers

and philosophers of science who seem to take

“consensus” as a practical synonym for sci-

entifi c knowledge (the author’s own position

THE ARGUMENT AGAINST TRUTH-CONDITIONAL SEMANTICS / 161

being that consensus is never suffi cient and its

necessity is only defeasible). Relatedly, hold-

ing that some disagreements entail occurrent

ignorance does not take one so far as Moses

Maimonides, who seems to hold that some

disagreements entail inescapable ignorance

(Sorensen 1988: p. 118).

Despite its comparative modesty, however,

CP may be suspected of defeating itself.

(a) CP is itself controversial. fact(b) CP is not known to be true. (a), CP(c) Invoking CP is unjustifi ed. (b)

Lines (a) and (b) are arguably right, but (c)

does not follow. To make the argument valid

would require some sort of bridge principle

like “if F is not known then F is never even

justifi ably posited,” which contradicts the

standard analysis of knowledge. Knowing

that there is controversy over a given matter

gives one reason to be especially cautious

and open-minded, and to abjure claims to

full knowledge; it does not by itself give one

reason to turn total skeptic, refusing even

tentative belief.

A related objection complains that if one

uses CP to judge TC semantics false then,

given fact (a'), one is committed to (b') and

perhaps (c'), which dooms the Argument from

Ignorance.

(a') It is controversial to call TC semantics

false. fact(b') It is not known that TC semantics is

false. (a), CP(c') Calling TC semantics false is unjusti-

fi ed. (b)

But this charge doesn’t stick. To start with,

dissent against TC semantics, even if it

could be said to reach the level of contro-

versy, is not necessarily controversial in the

right way. In order to have the right kind of

controversy, there cannot be any defeaters

of CP. Yet there are. For instance, because

truth-conditionalists have invested a great

deal of time, cognitive energy, and emotional

energy in mastering their tools of trade, e.g.,

intensional logic, they have a vested interest

in defending truth-conditionalism regardless

of its actual merits. Their opponents, on the

other hand, criticize truth-conditionalism

despite their standard investments in logic

and in the technical literature. Controversy

regarding TC semantics, therefore, is not

comparable to the controversy that dogs and

bogs vagueness theory.

More important, (b') is harmless. It does

not imply (c'), for the same reason that (b)

does not imply (c), and in itself it generates

no pragmatic contradiction. There is nothing

wrong with asserting “I do not know for sure,

but I’m going to say: P”—or even “I really

don’t know at all, but I think P is more worth

entertaining than its alternatives; therefore:

P”—or even “I’m sure that P will turn out to

be false, but for now I see no better alternative

than saying: P.” Line (b') is consistent with, in

fact demanded by, the humility that is proper

to semantic theory in the early twenty-fi rst

century (as is the claim that it is not known

that TC semantics is true).

In short, CP is sound, it leads to neither self-

defeat nor any other self-contradiction, and it

supports the conclusion that no one knows the

truth-conditions of (1). What’s more, in case

that is not convincing, section 1 has also ar-

gued that not everyone who knows the mean-

ing of (1) knows its truth-conditions. Either

conclusion, by itself, shows that knowledge

of meaning is not the same as knowledge of

truth-conditions.

To all appearances, then, knowledge of

meaning rarely if ever correlates with knowl-

edge of truth-conditions: one can have the

former without the latter. To this there are a

few possible replies. The Double Ignorance

Defense admits that speakers lack knowledge

of truth-conditions but contends that they

also lack knowledge of meaning (Saka 2007:

chap. 2.2). The Double Knowledge Defense

admits that speakers know the meanings of

the sentences they utter, but contends that they

162 / AMERICAN PHILOSOPHICAL QUARTERLY

also know their truth-conditions because they

possess either knowledge of disquotational T-

sentences, tacit knowledge, or inexact knowl-

edge (sections 3–5). Finally, the Argument

from Ignorance might be doubted because it

“proves too much.” These positions will be

described and discarded one by one.

III. Knowledge of T-Sentences

Terminological confusion in the literature

calls for some clarifi catory stipulations. A

disquotational T-sentence uses quotation on

one side of a biconditional, and the result of

removing quotation marks on the other:

(2) “The Queen of England is sitting in a

chair” is true iff the Queen of England is

sitting in a chair.

In a homophonic T-sentence, the two sides are

pronounced alike, as above and below:

(3) It is true that the Queen is sitting iff the

Queen is sitting.3

A metalinguistic T-sentence refers to some

object sentence (or utterance), be it by

means of quotation, structural description,

or otherwise:

(4) “Die Koenigin sitzt” is true iff the Queen

is sitting.

Disquotational T-sentences are both meta-

linguistic and homophonic. Because they

are metalinguistic, they allegedly specify the

truth-conditions of linguistic objects. And be-

cause they are homophonic, they allegedly are

known to hold a priori. Therefore, it is said, we

do know the truth-conditions of (1) because we

do know (2); more generally, for any sentence

at all we know its truth-conditions because we

know its (disquotational) T-sentence.

Against the general claim, it appears that

T-sentences do not give truth-conditions for

non-declaratives. This is not an easily ac-

commodated detail but actually a profound

problem (Saka 2007: chap. 2.1.1). Further-

more, if knowledge of (disquotational) T-sen-

tences gave knowledge of truth-conditions,

knowledge of (2), combined with relevant

knowledge of any arbitrary world, would

yield knowledge of (1)’s truth-value. Yet

it doesn’t. To see that this is so, imagine a

world where (1)’s truth is indefi nite. To de-

cide whether the Queen is sitting on a chair,

you run through a list of potentially relevant

factors, and in each case you imagine that the

factor is borderline. If you think that having

back support is relevant, you imagine a world

where the Queen is sitting on an object hav-

ing a marginal back; if you think that artifact

status is relevant, you imagine a world where

the Queen is sitting on an object produced

by forces that are neither defi nitely artifi cial

nor defi nitely natural; if you think consensus

of the linguistic community is relevant, you

imagine a world where exactly half of all

speakers affi rm (1) while exactly half deny it;

and so on. For any potentially relevant factor,

it is possible to imagine a world where the

obtaining of that factor is itself unsettled.

Another argument goes like this. You will

have a houseguest tonight, and your co-host

asks, “Do you know what he likes to drink?”

Although “He likes to drink what he likes to

drink” is true, it does not seem to count as

knowledge of what the guest likes to drink,

certainly not as relevant knowledge. At the

very minimum, if the tautology is all that you

know, then claiming to know what the guest

likes is outrageously misleading. By the same

token, if our only knowledge is that of T-sen-

tences, which are allegedly tautological, to

say that we have genuine knowledge of truth-

conditions is false or at least egregious.

Yet another argument comes from the

fi eld of translation. For instance, W. D. Ross

renders Aristotle’s defi nition of eudaimonia

as follows:

(5) Happiness is an activity of soul in ac-

cordance with perfect virtue.

According to the view under fi re, Ross knows

the disquotational T-sentences for both Aris-

totle’s utterance and (5), and furthermore this

THE ARGUMENT AGAINST TRUTH-CONDITIONAL SEMANTICS / 163

knowledge gives knowledge of truth-condi-

tions. It follows that Ross knows the truth-

conditions for both Aristotle’s utterance and

(5), in which case Ross should know whether

they are equivalent. But surely he doesn’t.

For presumably, like other diligent transla-

tors, Ross revised and revisited his transla-

tions, never sure that he had it exactly right,

indeed never sure that he had it as close as

he could get. In short, because disquotational

T-sentences drawn from two languages do not

allow for direct comparison by bilinguals,

they are but verbal formulas almost lacking

in substantive content.

More than that, ` shall actually reject the

view, expressed, for instance, by Larson and

Segal (1995: p. 30), that “T-sentences of the

following homophonic (disquotational) form

are (almost) always true.” Though Larson

and Segal note the liar paradox, they fail to

recognize its import. The liar paradox proves

that the universally generalized T-schema is

false, which means that specifi c instances of

the schema, to the extent that they are derived

from the schema, are invalid.

Despite Larson and Segal’s assertion, and

a chorus that holds T-sentences to be platitu-

dinously and necessarily true, the fact is that

disquotational T-sentences are never valid in

English. After all, every English sentence,

being infl ected for tense, calls for something

more full-blooded than bare homophony,

something along the lines of:

(6) If u is an utterance of “the Queen is sit-

ting” at time t then u is true iff the Queen

is, was, or will be sitting at t.

Deviations from homophony grow even

greater in the T-formulations for quantifi ed

sentences, adverbial sentences, and so forth,

as Larson and Segal themselves recognize.

Disquotational T-semantics, though it con-

tinues to loom large in the popular philo-

sophical imagination and though it persists in

programmatic pronunciamentos, is not taken

seriously by any concrete detailed natural-

language analysis.

To see that T-sentences are problematic,

consider their resemblance to R-sentences:

(R) “Cat” refers to cats.

Since the extension of “cat” appears to differ

from that of “cats,” if any expression at all

refers to cats, surely it is “cats” rather than

“cat.” Thus, (R) is less plausible than:

(R') “Cats” refers to cats.

But this too faces a challenge. Being in sub-

ject position, the fi rst word in (R') arguably

carries generic import, yet the last word, in

object position, does not, which would make

their extensions unequal. Partly for this rea-

son, perhaps, it is sometimes said that:

(R'') “Cats” refers to the set of cats.

Because sets are abstract objects, however,

being neither furry nor purry, (R'') mistak-

enly entails that “Cats are furry and purry”

is false. Presumably proponents of (R'') actu-

ally mean:

(R*) “Cats” refers to the members of the set

of cats.

But (R*), like (R''), falters on the problem of

vagueness. The extension of “cats” is vague,

while the extension of any set is precise.

Prima facie, then, it is astonishing to hear

that the extension of the one is exactly equal

to the extension of the other.

Whether the R-schema be valid or not, it is

no more a priori than the traditional platitude

that:

(E) The essence of justice is Justice.

Platonistic essentialism assumes that essences

exist, that Forms exist, and that essences are

Forms. But these are substantive assumptions,

and dressing them up in a pseudo-tautology

does not make them into truth. Likewise, the

R- and T-schemas, assuming that words refer

and sentences are true, cloak theoretical con-

tent that, true or no, is not self-certifying.

164 / AMERICAN PHILOSOPHICAL QUARTERLY

Perhaps one R-schema or another will

eventually prove defensible. Not one, how-

ever, is self-evident or immune to sincere

questioning. Likewise, the disquotational

T-schema is open to challenge. As just in-

dicated, both the T-schema and its instances

are analogous to the R-schemas, which are

suspect. More than that, as a universal gen-

eralization it is prima facie suspect because

of the liar paradox, while specifi c instances

of the T-schema are suspect because, argu-

ably, our only reason for believing them is

that they fl ow from the discredited universal

generalization (Saka 2007: chap. 8). Finally,

T-sentences fail for the reasons cited at (6).

And even if some T-sentences were true, this

would not automatically mean that they give

meaning. The most plausible T-sentences of

all, ordinary (non-metalinguistic), homopho-

nic T-sentences like (3), do not purport to be

about language, and hence prima facie say

nothing about meaning.

For those already committed to TC seman-

tics it may appear that T-sentences provide

truth-conditions, but there is no available

argument that they do. On the contrary,

there are arguments that they positively do

not. Those arguments, to repeat, are (i) that

T-sentences do not treat non-declaratives; (ii)

that you can know that a T-sentence holds,

and be omniscient as regards non-linguistic

fact, and you will not know whether an

object sentence is true; (iii) knowledge of a

tautology does not give genuine knowledge

of the relevant kind; (iv) you can know two

languages, including the T-sentences that go

with them, without knowing whether a pro-

posed translation preserves truth-conditions;

and (v) disquotational T-sentences are false.

One day, perhaps, their kinship to essentialist

dogma (E) will be recognized.

IV. Tacit Knowledge

Truth-conditionalists might maintain that

speakers really do know the truth-conditions

of vague statements, it’s just that they can-

not articulate them, they have no conscious

access to them, they do not all know that we

know them. Knowledge of truth-conditions

exists but is not explicitly propositional, it

takes the form of know-how, it is implicit, or

it is tacit. Unfortunately, to do this proposal

justice is diffi cult—partly because several

beasts are prowling around here, not just one,

and partly because they are lurking, being

neither bagged nor tagged. What follows will

necessarily be sketchy.

Discussions of tacit semantic knowledge as

do exist seem always to address knowledge of

axioms, taking it for granted that knowledge

of T-sentences is explicit (Evans 1981, Davies

1989, Wright 1993, Larson and Segal 1995,

Platts 1997). But this is just not true, as we’ve

seen for both full-blooded T-sentences (section

1) and disquotational T-sentences (section 3).

Another tack is to suggest that knowledge

of truth-conditions is an ability, a skill, a

knack, know-how. Since know-how can be

inarticulable and inaccessible to conscious-

ness, knowledge of truth-conditions can be

too. But this suggestion can’t be taken liter-

ally. The object of know-how is an action:

one knows how to ride a bike, how to throw a party, 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. Knowledge of truth-conditions is

not know-how.

Instead of saying that to know the meaning

of P is to know P’s truth-conditions, can we

say that to know the meaning of P is to know

how to pair P with P’s truth-conditions? The

notion of pairing requires explication. If to

pair P with condition-type C is to express

P iff C obtains, then knowledge of meaning

would issue in all and only true statements,

which is absurd. To pair P with some mental representation of C, though that may threaten

TC semantics in favor of mentalist semantics,

is more promising.

THE ARGUMENT AGAINST TRUTH-CONDITIONAL SEMANTICS / 165

Cognitive scientists often posit mental

representations, or otherwise ascribe proposi-

tional knowledge, in order to explain a subject

S’s motor skills, visual recognition abilities,

grammatical competence, 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 propo-

sitional knowledge) or that S’s knowledge is

either linguistically encoded or accessible to

S’s consciousness. They claim a mere virtual equivalence: that, in principle, those possess-

ing the knowledge in question would be able

to exhibit S’s abilities. For instance, in describ-

ing or explaining the particular inferences that

S makes, we might attribute to S the schematic

knowledge that {f, f → y} entails y even if S

lacks explicit knowledge of set theory, Greek

letters, and the concept of metavariables.

This “virtual equivalence” view poses dif-

fi culties that must be passed over here, but

more importantly it misses the point of the

Argument from Ignorance. This argument

never denied to speakers knowledge of Tar-

skian truth-theoretic or Montagovian pos-

sible-world formulas (which would be true

but beside the point). What is denied is that

speakers are even virtually equivalent to any

mechanism that did have such knowledge.

Speakers do not possess the appropriate com-

petence—for instance, to judge whether (1) is

true in an arbitrary world or to draw all and

only valid inferences from (1)—that would

justify ascribing truth-conditional knowledge

to them. Ascribing TC knowledge to some-

one who does not know the truth-value of a

statement under a particular condition, even

when asked to think about it, is like ascrib-

ing knowledge of the rule of modus ponens

to someone who cannot decide whether any

given instance of it is valid.

The proposal on the table, which treats

knowledge of truth-conditions in some at-

tenuated form, runs afoul of the KK thesis,

privileged access, and related claims of infal-

libility. That is hardly fatal, for infallibilism

is untenable. Still, it seems plausible to think

that second-order thoughts possess a kind

of conditional, defeasible reliability: if you

believe upon refl ection that you don’t believe

P then you are right to believe you don’t be-

lieve P, unless some reason can be given for

why you might be deluded. Is there reason to

think we might possess semantic knowledge

without knowing what it is? Already consid-

ered, and rejected, is the idea that semantic

knowledge is not consciously propositional

because it is an example of know-how has.

Next up are the possibilities that pragmatic

distractors cloud semantic knowledge, that

theoretical bias contributes to self-deceit; and

that margins of error create “inexactitude.”

The fi rst possibility is that pragmatic fac-

tors cloud the semantic facts. This sort of

confusion is illustrated by careless speakers

who read (7) as stating (8), though it does no

such thing.

(7) I’ve had a perfectly wonderful evening.

(8) I’ve had a perfectly wonderful evening

tonight.

Pragmatic inferences, be they based on Grice-

an 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 sometimes

identifi able. For if it weren’t, there would be

no way to tell whether Gricean principles can

carry us from the posited semantic content to

the experienced pragmatic content; indeed,

there would never have been any impulse

in the fi rst place to postulate a layer of real

content together with machinery for explain-

ing apparent content. Yet truth-conditions are

virtually never identifi able. What’s more,

there are methods for blowing pragmatic

fog away from TC content, for instance the

cancellability test (Sadock 1978). We can,

without contradiction, assert (8) while cancel-

ing its implicature (9):

166 / AMERICAN PHILOSOPHICAL QUARTERLY

(9) I’ve had a perfectly wonderful evening.

But this wasn’t it. (Groucho Marx)

This establishes, what sensitive speakers

already knew, that in saying (7) one does not

thereby say (8).

Neither established tests for pragmatic

effects, nor sensitivity as measured by agree-

ment among language experts who have

refl ected on the matter (be they in literature,

linguistics, law, or philosophy), hints that

grasping vague statements, deep down, con-

sists of grasping truth-conditions. It follows

that, so far as vagueness goes, truth-condi-

tions are not veiled by implicature or any

other known pragmatic effect, and when

speakers disagree about truth-conditions it is

not because they are obtuse. Rather, knowl-

edge of truth-conditions does not exist.

Perhaps apparent ignorance regarding

truth-conditions is a result of self-deceit,

contradictory thinking, or distortion. Perhaps

commitment to a particular semantic theory

has led scholars to introduce spurious truth-

conditions into their thinking and to deny to

themselves what they really know or to forget

what they once knew. This phenomenon,

where the object of linguistic inquiry appears

to change under introspective observation, is

notoriously commonplace in the disciplines

of syntax and phonology, and it should not

be surprising for us to fi nd it in semantics.

The problem is that it’s also found among

non-semanticists who have no axes to grind.

Classroom audiences, utterly naive about

linguistics and theories of meaning, have been

asked to judge whether statements of the form

“P or not-P” are always true, sometimes false,

or ever both true and false, and they always

divide on the issue. Mistaken they may be, but

deluded by professional bias and theoretical

distortion they are not.

V. Inexact Knowledge

Williamson (1994) holds that we know the

truth-conditions of our statements, but mar-

gins of error make our knowledge inexact,

where inexactitude blocks the KK principle.

The basic idea is that knowledge is connected

to reliability and probability, which do not

iterate: a 90 percent chance of rain does not

mean that there is a 90 percent chance of

there being a 90 percent chance of rain. In

this way, our knowledge of truth-conditions

does not yield knowledge of knowledge, or

even knowledge of certain related matters.

For example, if unambiguous utterance u

expresses the (truth-conditional) proposition

P then we know that u expresses P, even if we

do not know that we know it, and even if we

do not know that u does not express distinct

proposition Q. Thus, suppose that the Queen

is sitting on a broken heap that once was a

chair, P is a proposition or set of conditions

that counts broken erstwhile chairs as chairs,

and Q counts broken erstwhile chairs as non-

chairs. Then if (1) says P, (1) is true; if (1) says

Q, (1) is false; and speakers know full well

which proposition is asserted by (1), accord-

ing to Williamson. What they don’t know is

which propositions are not asserted by (1).

However, the following argument indicates

that if one did know that u said P, one would

easily know a great deal about which proposi-

tions are not expressed by u. Here, K stands

for “speakers know that”:

(a) K(u says P)

(b) K(u says P → ~u says Q)

(c) K(~u says Q)

Williamson accepts the inference but rejects

premise (b); the bare conditional is true, he

says, but that does not mean that anyone

knows that it is true, for P and Q may be in-

discriminable (p. 235). He may well be right

in the general case, though crucially not in all.

To see this, let P = “there is a heap of sand,”

which is truth-conditionally the same, for

Williamson, as P' = “there are at least n grains

of sand,” for some defi nite n (setting aside is-

sues of the confi guration of the grains). Now

we can distinguish between P', and Q = “there

THE ARGUMENT AGAINST TRUTH-CONDITIONAL SEMANTICS / 167

are at least n+1 grains of sand.” Therefore,

by Williamsonian lights we should be able to

distinguish between P and Q, in which case

line (b) holds. This means that rejecting (a)

is the only way to block the unacceptable (c),

and hence inexact knowledge does not really

account for lack of TC knowledge.

Nor does inexact knowledge account for

lack of TC belief. It’s not just that one doesn’t

know whether one knows that broken chairs

are chairs—one neither believes that they are

nor believes that they aren’t. But such agnos-

ticism is incompatible with one’s actually

knowing the truth-conditions of (1), assuming

the standard analysis of knowledge, that it is

a kind of belief.

In trying to motivate his treatment of vague-

ness as a species of inexact knowledge, Wil-

liamson refers to

a (fallible) mechanism [M] for recognizing

the property of thinness. Although everything

has or lacks the property, the reliability of the

mechanism depends on its giving neither a

positive nor a negative response in marginal

cases. (p. 208)

But is this right? For the sake of simplicity,

suppose that M blinks green in response to

waists under size 30, M blinks red in response

to waists over size 40, and M does nothing in

all other cases. Then instead of teleologically

assuming that M vaguely registers the strictly

bivalent property of thinness, as Williamson

does, a naturalistic description would seem to

be that M precisely registers two properties,

that of being under 30 and that of being over

40. It seems that the motivating spirit behind

inexact knowledge, as well as its application

to truth-conditions, are both implausible.

In sum, a number of possible explanations

for how we might know truth-conditions with-

out being aware of them have been considered.

The idea that margins of error create inexact

knowledge—full precise knowledge that exists

but is not known to exist—has just been reject-

ed. The idea of theorist’s prejudice, or related

problems arising from refl exive theorizing,

fails because uncertainty and disagreement

regarding truth-conditions can be found in lay

populations. The idea of pragmatic confusion

is unconvincing; if this were the right story,

then careful and trained scholars should be able

to agree on truth-conditions, whereas in fact

there are even more viewpoints represented

among experts than in the lay population. The

idea of virtual knowledge is unhelpful because

virtual knowledge is supposed to explain mani-

fest skills. While attribution of knowledge of

truth-conditions would explain how speakers

can systematically reach judgments about

the truth-values of sentences, speakers in fact

lack this ability; hence positing a means for

explaining it does not make sense.

The present argument against truth-condi-

tional semantics derives from disagreement

among truth-conditional semanticists. Does

it not follow, then, that wider disagreement

among semanticists more generally makes for

an argument against there being any meaning

whatsoever? And if so, do we not have a re-

ductio against the Argument from Ignorance,

even if its exact fl aw cannot be identifi ed?

The objection mistakenly assumes that

semantic theory must relate knowledge of

meaning to knowledge of some x. (Such

would be plausible only given an ontic rela-

tion between meaning and x. But the latter

arguably requires meaning to be an entity,

which is doubtful.) Perhaps to know the

meaning of P is to be able to communicate

using P, and to communicate using P is to be

able to verbally coordinate certain activities

with others. Since speakers of a common

language are in fact able to coordinate many

of their activities by use of language, this

pragmatic view plausibly stands whereas the

epistemic correlation between meaning and

truth-conditions manifestly falls.4

University of Houston

168 / AMERICAN PHILOSOPHICAL QUARTERLY

NOTES

1. Lycan (1984: p. 295) wonders at the interchangeable use of “truth-condition” and “truth-conditions.”

The singular picks out a kind while the plural picks out a set of particulars.

2. This characterization suits truth-theoretic as well as model-theoretic semantics, inasmuch as

extensional T-conditions are effectively necessary and suffi cient conditions, arising as they do from

counterfactual-supporting axioms (Davidson 1984: pp. 24, 26). That which is distinctive about truth-

theoretic semantics is addressed in section 3.

3. Actually, so-called homophonic T-sentences must owe their homophony to more than chance, namely

to the repetition of identical words and syntax; “homo-sentential T-sentences” or “iso-T-sentences”

would be more apt.

4. For encouragement and helpful comments on earlier drafts, the author would like to thank Jonathan

Adler, Justin Leiber, Bill Lycan, Rob Stainton, anonymous reviewers, and audience members far and

wide.

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