## 1. Two Kinds of Theory of Meaning



In "General Semantics", David Lewis wrote



> 
> 
> I distinguish two topics: first, the description of possible languages
> or grammars as abstract semantic systems whereby symbols are
> associated with aspects of the world; and, second, the description of
> the psychological and sociological facts whereby a particular one of
> these abstract semantic systems is the one used by a person or
> population. Only confusion comes of mixing these two topics. (Lewis
> 1970: 19)
> 
> 
> 



Lewis was right. Even if philosophers have not consistently kept these
two questions separate, there clearly is a distinction between the
questions "What is the meaning of this or that symbol (for a
particular person or group)?" and "In virtue of what facts
about that person or group does the symbol have that
meaning?"



Corresponding to these two questions are two different sorts of theory
of meaning. One sort of theory of meaning--a *semantic
theory*--is a specification of the meanings of the words and
sentences of some symbol system. Semantic theories thus answer the
question, "What is the meaning of this or that
expression?" A distinct sort of theory--a *foundational
theory of meaning*--tries to explain what about some person
or group gives the symbols of their language the meanings that they
have. To be sure, the shape of a correct semantic theory places
constraints on the correct foundational theory of meaning, and vice
versa; but that does not change the fact that semantic theories and
foundational theories are simply different sorts of theories, designed
to answer different questions.



To see the distinction between semantic theories and foundational
theories of meaning, it may help to consider an analogous one. Imagine
an anthropologist specializing in table manners sent out to observe a
distant tribe. One task the anthropologist clearly might undertake is
to simply describe the table manners of that tribe--to describe
the different categories into which members of the tribe place actions
at the table, and to say which sorts of actions fall into which
categories. This would be analogous to the task of the philosopher of
language interested in semantics; her job is say what different sorts
of meanings expressions of a given language have, and which
expressions have which meanings.



But our anthropologist might also become interested in the nature of
manners; he might wonder how, in general, one set of rules of table
manners comes to be the system of etiquette governing a particular
group. Since presumably the fact that a group obeys one system of
etiquette rather than another is traceable to something about that
group, the anthropologist might put his new question by asking, 



> 
> 
> In virtue of what facts about a person or group does that person or
> group come to be governed by a particular system of etiquette, rather
> than another? 
> 
> 
> 



Our anthropologist would then have embarked upon the analogue of the
construction of a foundational theory of meaning: he would then be
interested, not in which etiquette-related properties particular
action types have in a certain group, but rather the question of how
action-types can, in any group, come to acquire properties of this
 sort.[1]
 Our anthropologist might well be interested in both sorts of
questions about table manners; but they are, pretty clearly, different
questions. Just so, semantic theories and foundational theories of
meaning are, pretty clearly, different sorts of theories.



The term "theory of meaning" has, in the recent history of
philosophy, been used to stand for both semantic theories and
foundational theories of meaning. As this has obvious potential to
mislead, in what follows I'll avoid the term which this article
is meant to define and stick instead to the more specific
"semantic theory" and "foundational theory of
meaning". "Theory of meaning" *simpliciter*
can be understood as ambiguous between these two
interpretations.



Before turning to discussion of these two sorts of theories, it is
worth noting that one prominent tradition in the philosophy of
language denies that there are facts about the meanings of linguistic
expressions. (See, for example, Quine 1960 and Kripke 1982; for
critical discussion, see Soames 1997.) If this sort of skepticism
about meaning is correct, then there is neither a true semantic theory
nor a true foundational theory of meaning to be found, since the
relevant sort of facts simply are not around to be described or
analyzed. Discussion of these skeptical arguments is beyond the scope
of this entry, so in what follows I'll simply assume that
skepticism about meaning is false.


## 2. Semantic Theories



The task of explaining the main approaches to semantic theory in
contemporary philosophy of language might seem to face an in-principle
stumbling block. Given that no two languages have the same
semantics--no two languages are comprised of just the same words,
with just the same meanings--it may seem hard to see how we can
say anything about different views about semantics in general, as
opposed to views about the semantics of this or that language. This
problem has a relatively straightforward solution. While it is of
course correct that the semantics for English is one thing and the
semantics for French something else, most assume that the various
natural languages should all have semantic theories of (in a sense to
be explained) the same form. The aim of what follows will,
accordingly, be to introduce the reader to the main approaches to
natural language semantics--the main views about the right form
for a semantics for a natural language to take--rather than to provide a
detailed examination of the various views about the semantics of some
particular expression. (For an overview, see the entry on
 word meaning.
 For discussion of issues involving particular expression types, see
the entries on
 names,
 quantifiers and quantification,
 descriptions,
 propositional attitude reports, and
 natural kinds.)



One caveat before we get started: before a semantic theorist sets off
to explain the meanings of the expressions of some language, she needs
a clear idea of what she is supposed to explain the meaning
*of*. This might not seem to present much of a problem;
aren't the bearers of meaning just the sentences of the relevant
language, and their parts? This is correct as far as it goes. But the
task of explaining what the semantically significant parts of a
sentence are, and how those parts combine to form the sentence, is as
complex as semantics itself, and has important consequences for
semantic theory. Indeed, most disputes about the right semantic
treatment of some class of expressions are intertwined with questions
about the syntactic form of sentences in which those expressions
figure. Unfortunately, discussion of theories of this sort, which
attempt to explain the syntax, or logical form, of natural language
sentences, is well beyond the scope of this entry. As a result,
figures like Richard Montague, whose work on syntax and its connection
to semantics has been central to the development of semantic theory
over the past few decades, are passed over in what
follows. (Montague's essays are collected in Montague 1974.) For
an excellent introduction to the connections between syntax and
semantics, see Heim & Kratzer (1998); for an overview of the
relations between philosophy of language and several branches of
linguistics, see Moss (2012).



There are a wide variety of approaches to natural language semantics.
My strategy in what follows will be to begin by explaining one
prominent family of approaches to semantics which developed over the
course of the twentieth century and is still prominently represented
in contemporary work in semantics, both in linguistics and in
philosophy. For lack of a better term, let's call these types of
semantic theories *classical semantic theories*. (As in
discussions of classical logic, the appellation
"classical" is not meant to suggest that theories to which
this label is applied are to be preferred over others.) Classical
semantic theories agree that sentences are (typically) true or false,
and that whether they are true or false depends on what information
they encode or express. This "information" is often called
"the proposition expressed by the sentence". The job of a
semantic theory, according to the classical theorist, is at least in
large part to explain how the meanings of the parts of the sentence,
along with the context in which the sentence is used, combine to
determine which proposition the sentence expresses in that context
(and hence also the truth conditions of the sentence, as used in that
context).



Classical semantic theories are discussed in
 SS2.1.
In
 SSSS2.1.1-4
 the theoretical framework common to classical semantic
theories is explained; in
 SSSS2.1.5-7
the differences between three main versions of classical
semantic theories are explained. In
 SS2.2
 there is a discussion of the alternatives to classical semantic theories. 
 In 
 SS2.3
 few general concluding questions are discussed; these are questions
 semantic theorists face
which are largely, though not completely, orthogonal to one's
view about the form which a semantic theory ought to take.


### 2.1 Classical Semantic Theories



The easiest way to understand the various sorts of classical semantic
theories is by beginning with another sort of theory: a theory of
reference.


#### 2.1.1 The theory of reference



A theory of reference is a theory which pairs expressions with the
contribution those expressions make to the determination of the
truth-values of sentences in which they occur. (Though later we will
see that this view of the reference of an expression must be
restricted in certain ways.)



This construal of the theory of reference is traceable to
 Gottlob Frege's
 attempt to formulate a logic sufficient for the formalization of
mathematical inferences (see especially Frege 1879 and 1892.) The
construction of a theory of reference of this kind is best illustrated
by beginning with the example of proper names. Consider the following
sentences:


* (1)
Barack Obama was the 44th president of the United States.
* (2) John
McCain was the 44th president of the United States.



(1) is true, and (2) is false. Obviously, this difference in
truth-value is traceable to some difference between the expressions
"Barack Obama" and "John McCain". What about
these expressions explains the difference in truth-value between these
sentences? It is very plausible that it is the fact that "Barack
Obama" stands for the man who was in fact the 44th president of
the United States, whereas "John McCain" stands for a man
who was not. This suggests that the reference of a proper
name--its contribution to the determination of truth conditions
of sentences in which it occurs--is the object for which that
name stands. (While this is plausible, it is not uncontroversial that
the purpose of a name is to refer to an individual; see Graff Fara
(2015) and Jeshion (2015) for arguments on opposite sides of this
issue.)



Given this starting point, it is a short step to some conclusions
about the reference of other sorts of expressions. Consider the
following pair of sentences:


* (3)
Barack Obama is a Democrat.
* (4)
Barack Obama is a Republican.



Again, the first of these is true, whereas the second is false. We
already know that the reference of "Barack Obama" is the
man for which the name stands; so, given that reference is power to
affect truth-value, we know that the reference of *predicates*
like "is a Democrat" and "is a Republican"
must be something which combines with an object to yield a
truth-value. Accordingly, it is natural to think of the reference of
predicates of this sort as functions from objects to truth-values. The
reference of "is a Democrat" is that function which
returns the truth-value "true" when given as input an
object which is a member of the Democratic party (and the truth-value
"false" otherwise), whereas the reference of "is a
Republican" is a function which returns the truth-value
"true" when given as input an object which is a member of
the Republican party (and the truth-value "false"
otherwise). This is what explains the fact that (3) is true and (4)
false: Obama is a member of the Democratic party, and is not a member
of the Republican party.



Matters get more complicated, and more controversial, as we extend
this sort of theory of reference to cover more and more of the types
of expressions we find in natural languages like English. (For an
introduction, see Heim and Kratzer (1998).) But the above is enough to
give a rough idea of how one might proceed. For example, some
predicates, like "loves" combine with two names to form a
sentence, rather than one. So the reference of two-place predicates of
this sort must be something which combines with a pair of objects to
determine a truth-value--perhaps, that function from ordered
pairs of objects to truth-values which returns the truth-value
"true" when given as input a pair of objects whose first
member loves the second member, and "false" otherwise.


#### 2.1.2 Theories of reference vs. semantic theories



So let's suppose that we have a theory of reference for a
language, in the above sense. Would we then have a satisfactory
semantic theory for the language?



Some plausible arguments indicate that we would not. To adopt an
example from Quine (1970 [1986], pp. 8-9), let's assume
that the set of animals with hearts (which Quine, for convenience,
calls "cordates" - not to be confused with
"chordates") is the same as the set of animals with
kidneys (which Quine calls "renates"). Now, consider the
pair of sentences:


* (5)
All cordates are cordates.
* (6)
All cordates are renates.



Given our assumption, both sentences are true. Moreover, from the
point of view of the theory of reference, (5) and (6) are just the
same: they differ only in the substitution of "renates"
for "cordates", and these expressions have the same
reference (because they stand for the same function from objects to
truth-values).



All the same, there is clearly an intuitive difference in meaning
between (5) and (6); the sentences seem, in some sense, to say
different things. The first seems to express the trivial, boring
thought that every creature with a heart is a creature with a heart,
whereas the second expresses the non-trivial, potentially informative
claim that every creature with a heart also has a kidney. This
suggests that there is an important difference between (5) and (6)
which our theory of reference simply fails to capture.



Examples of the same sort can be generated using pairs of expressions
of other types which share a reference, but intuitively differ in
meaning; for example, "Clark Kent" and
"Superman", or (an example famously discussed by Frege
(1892 [1960]), "the Morning Star" and "the Evening
Star".



This might seem a rather weak argument for the incompleteness of the
theory of reference, resting as it does on intuitions about the
relative informativeness of sentences like (5) and (6). But this
argument can be strengthened by embedding sentences like (5) and (6)
in more complex sentences, as follows:


* (7)
John believes that all cordates are *cordates*.
* (8)
John believes that all cordates are *renates*.



(7) and (8) differ only with respect to the italic expressions and, as
we noted above, these expressions have the same reference. Despite
this, it seems clear that (7) and (8) could differ in truth-value:
someone could know that all cordates have a heart without having any
opinion on the question of whether all cordates have a kidney. But
that means that the references of expressions don't even do the
job for which they were introduced: they don't explain the
contribution that expressions make to the determination of the
truth-value of all sentences in which they occur. (One might, of
course, still think that the reference of an expression explains its
contribution to the determination of the truth-value of a suitably
delimited class of simple sentences in which the expression occurs.)
If we are to be able to explain, in terms of the properties of the
expressions that make them up, how (7) and (8) can differ in
truth-value, then expressions must have some other sort of value, some
sort of meaning, which goes beyond reference.



(7) and (8) are called *belief ascriptions*, for the obvious
reason that they ascribe a belief to a subject. Belief ascriptions are
one sort of *propositional attitude ascription*--other
types include ascriptions of knowledge, desire, or judgment. As will
become clear in what follows, propositional attitude ascriptions have
been very important in recent debates in semantics. One of the reasons
why they have been important is exemplified by (7) and (8). Because
these sentences can differ in truth-value despite the fact that they
differ only with respect to the italic words, and these words both
share a reference and occupy the same place in the structure of the
two sentences, we say that (7) and (8) contain a *non-extensional
context*: roughly, a "location" in the sentence which
is such that substitution of terms which share a reference in that
location can change truth-value. (They're called
"non-extensional contexts" because "extension"
is another term for "reference".)



We can give a similar argument for the incompleteness of the theory of
reference based on the substitution of whole sentences. A theory of
reference assigns to subsentential expressions values which explain
their contribution to the truth-values of sentences; but to those
sentences, it only assigns "true" or "false".
But consider a pair of sentences like


* (9) Mary
believes that *Barack Obama was the president of the United
States*.
* (10)
Mary believes that *John Key was the prime minister of New
Zealand*.



Because both of the italic sentences are true, (9) and (10) are a pair
of sentences which differ only with respect to substitution of
expressions (namely, the italic sentences) with the same reference.
Nonetheless, (9) and (10) could plainly differ in truth-value.



This seems to show that a semantic theory should assign some value to
sentences other than a truth-value. Another route to this conclusion
is the apparent truth of claims of the following sort:


* There are three things that John believes about Indiana, and they
are all false.
* There are many necessary truths which are not *a priori*,
and my favorite sentence expresses one of them.
* To get an A you must believe everything I say.



Sentences like these seem to show that there are things which are the
objects of mental states like belief, the bearers of truth and falsity
as well as modal properties like necessity and possibility and
epistemic properties like a prioricity and posterioricity, and the
things expressed by sentences. What are these things? The theory of
reference provides no answer.



These entities are often called *propositions*. Friends of
propositions aim both to provide a theory of these entities, and, in
so doing, also to solve the two problems for the theory of reference
discussed above: (i) the lack of an explanation for the fact that
 (5)
 is trivial while
 (6)
 is not, and (ii) the fact (exemplified by
 (7)/(8)
 and
 (9)/(10))
 that sentences which differ only in the substitution of expressions
with the same reference can differ in truth-value.



A theory of propositions thus does not abandon the theory of
reference, as sketched above, but simply says that there is more to a
semantic theory than the theory of reference. Subsentential
expressions have, in addition to a reference, a *content*. The
contents of sentences--what sentences express--are known as
*propositions*.


#### 2.1.3 The relationship between content and reference



The natural next question is: What sorts of things are contents? Below
I'll discuss some of the leading answers to this question. But
in advance of laying out any theory about what contents are, we can
say some general things about the role that contents are meant to
play.



First, what is the relationship between content and reference?
Let's examine this question in connection with sentences; here
it amounts to the question of the relationship between the proposition
a sentence expresses and the sentence's truth-value. One point
brought out by the example of
 (9)
 and
 (10)
 is that two sentences can express different propositions while having
the same truth-value. After all, the beliefs ascribed to Mary by these
sentences are different; so if propositions are the objects of belief,
the propositions corresponding to the italic sentences must be
different. Nonetheless, both sentences are true.



Is the reverse possible? Can two sentences express the same
proposition, but differ in truth-value? It seems not, as can be
illustrated again by the role of propositions as the objects of
belief. Suppose that you and I believe the exact same thing--both
of us believe the world to be just the same way. Can my belief be
true, and yours false? Intuitively, it seems not; it seems incoherent
to say that we both believe the world to be the same way, but that I
get things right and you get them wrong. (Though see the discussion of
relativism in
 SS2.3.2
 below for a dissenting view.) So it seems that if two sentences
express the same proposition, they must have the same truth value.



In general, then, it seems plausible that two sentences with the same
content--i.e., which express the same proposition--must
always have the same reference, though two expressions with the same
reference can differ in content. This is the view stated by the
Fregean slogan that sense determines reference ("sense"
being the conventional translation of Frege's *Sinn*,
which was his word for what we are calling "content").



If this holds for sentences, does it also hold for subsentential
expressions? It seems that it must. Suppose for reductio that two
subsentential expressions, *e* and *e\**, have the same
content but differ in reference. It seems plausible that two sentences
which differ only by the substitution of expressions with the same
content must have the same content. (While plausible, this principle
is not uncontroversial; see entry on
 compositionality.)
 But if this is true, then sentences which differ only in the
substitution of *e* and *e\** would have the same content.
But such a pair of sentences could differ in truth-value, since, for
any pair of expressions which differ in reference, there is some pair
of sentences which differ only by the substitution of those
expressions and differ in truth-value. So if there could be a pair of
expressions like *e* and *e\**, which differ in their
reference but not in their content, there could be a pair of sentences
which have the same content--which express the same
proposition--but differ in truth-value. But this is what we
argued above to be impossible; hence there could be no pair of
expressions like *e* and *e\**, and content must determine
reference for subsentential expressions as well as sentences.



This result--that content determines reference--explains one
thing we should, plausibly, want a semantic theory to do: it should
assign to each expression some value--a content--which
determines a reference for that expression.


#### 2.1.4 Character and content, context and circumstance



However, there is an obvious problem with the idea that we can assign
a content, in this sense, to all of the expressions of a language like
English: many expressions, like "I" or "here",
have a different reference when uttered by different speakers in
different situations. So we plainly cannot assign to "I" a
single content which determines a reference for the expression, since
the expression has a different reference in different situations.
These "situations" are typically called *contexts of
utterance*, or just *contexts*, and expressions whose
reference depends on the context are called
 indexicals (see entry)
 or *context-dependent expressions*.



The obvious existence of such expressions shows that a semantic theory
must do more than simply assign contents to every expression of the
language. Expressions like "I" must also be associated
with rules which determine the content of the expression, given a
context of utterance. These rules, which are (or determine) functions
from contexts to contents, are called *characters*. (The
terminology here, as well as the view of the relationship between
context, content, and reference, is due to Kaplan (1989).) So the
character of "I" must be some function from contexts to
contents which, in a context in which I am the speaker, delivers a
content which determines me as reference; in a context in which Barack
Obama is the speaker, delivers a content which determines Barack Obama
as reference; and so on. (See figure 1.) 



![diagram with text: link to extended description below](character-content.gif)

Figure 1. [An
 extended description of figure 1
 is in the supplement.]




Here we face another potentially misleading ambiguity in
"meaning". What is the real *meaning* of an
expression--its character, or its content (in the relevant
context)? The best answer here is a pluralist one. Expressions have
characters which, given a context, determine a content. We can talk
about either character or content, and both are important. The
important thing is to be clear on the distinction, and to see the
reasons for thinking that expressions have both a character and
(relative to a context) a content.



How many indexical expressions are there? There are some obvious
candidates--"I", "here",
"now", etc.--but beyond the obvious candidates, it is
very much a matter of dispute; for discussion, see
 SS2.3.1
 below.



But there is a kind of argument which seems to show that almost every
expression is an indexical. Consider an expression which does not seem
to be context-sensitive, like "the second-largest city in the
United States". This does not seem to be context-sensitive,
because it seems to refer to the same city--Los
Angeles--whether uttered by me, you, or some other English
speaker. But now consider a sentence like


* (11) 100
years ago, the second-largest city in the United States was
Chicago.



This sentence is true. But for it to be true, "the
second-largest city in the United States" would have to, in
(11), refer to Chicago. But then it seems like this expression must be
an indexical--its reference must depend on the context of
utterance. In (11), the thought goes, the phrase "one hundred
years ago" shifts the context: in (11), "the
second-largest city in the United States" refers to that city
that it would have referred to if uttered one hundred years ago.



However, this can't be quite right, as is shown by examples like
this one:


* (12) In 100
years, I will not exist.



Let's suppose that this sentence, as uttered by me, is true.
Then, if what we said about
 (11)
 was right, it seems that "I" must, in, (12), refer to
whoever it would refer to if it were uttered 100 years in the future.
So the one thing we know is that (assuming that (12) is true), it does
not refer to me--after all, I won't be around to utter
anything. But, plainly, the "I" in (12) *does*
refer to me when this sentence is uttered by me--after all, it is
a claim about me. What's going on here?



What examples like (12) are often taken to show is that the reference
of an expression must be relativized, not just to a context of
utterance, but also to a *circumstance of
evaluation*--roughly, the possible state of the world
relevant to the determination of the truth or falsity of the sentence.
In the case of many simple sentences, context and circumstance
coincide; details aside, they both just are the state of the world at
the time of the utterance, with a designated speaker and place. But
sentences like (12) show that they can come apart. Phrases like
"In 100 years" shift the circumstance of
evaluation--they change the state of the world relevant to the
evaluation of the truth or falsity of the sentence--but
don't change the context of utterance. That's why when I
utter (12), "I" refers to me--despite the fact that I
won't exist to utter it in 100 years time.



![diagram with text: link to extended description below](2-index.gif)

Figure 2. [An
 extended description of figure 2
 is in the supplement.]




This is sometimes called the need for *double-indexing
semantics*--the two indices being contexts of utterance and
circumstances of evaluation. (See figure 2.)



The classic explanation of a double-indexing semantics is Kaplan
(1989); another important early discussion is Kamp (1971). For a
different interpretation of the framework, see David Lewis (1980). For
a classic discussion of some of the philosophical issues raised by
indexicals, see Perry (1979).



Double-indexing explains how we can regard the reference of "the
second-largest city in the United States" in
 (11)
 to be Chicago, without taking "the second-largest city in the
United States" to be an indexical like "I". On this
view, "the second-largest city in the United States" does
not vary in content depending on the context of utterance; rather, the
content of this phrase is such that it determines a different
reference with respect to different circumstances of evaluation. In
particular, it has Los Angeles as its reference with respect to the
present state of the actual world, and has Chicago as its reference
with respect to the state of actual world 100 years
 ago.[2]
 Because "the second-largest city in the United States"
refers to different things with respect to different circumstances, it
is not a
 rigid designator (see entry)--these
 being expressions which (relative to a context of utterance) refer to
the same object with respect to every circumstance of evaluation at
which that object exists, and never refer to anything else with
respect to another circumstance of evaluation. (The term "rigid
designator" is due to Kripke [1972].)



(Note that this particular example assumes the highly controversial
view that circumstances of evaluation include, not just possible
worlds, but also times. For a discussion of different views about the
nature of circumstances of evaluation and their motivations, see
 SS2.3.2
 below.)


#### 2.1.5 Possible worlds semantics



So we know that expressions are associated with characters, which are
functions from contexts to contents; and we know that contents are
things which, for each circumstance of evaluation, determine a
reference. We can now raise a central question of (classical) semantic
theories: what sorts of things are contents? The foregoing suggests a
pleasingly minimalist answer to this question: perhaps, since contents
are things which together with circumstances of evaluation determine a
reference, contents just *are* functions from circumstances of
evaluation to a reference.



This view sounds abstract but is, in a way, quite intuitive. The idea
is that the meaning of an expression is not what the expression stands
for in the relevant circumstance, but rather a rule which tells you
what the expression would stand for if the world were a certain way.
So, on this view, the content of an expression like "the tallest
man in the world" is not simply the man who happens to be
tallest, but rather a function from ways the world might be to
men--namely, that function which, for any way the world might be,
returns as a referent the tallest man in that world (if there is one,
and nothing otherwise). This fits nicely with the intuitive idea that
to understand such an expression one needn't know what the
expression actually refers to--after all, one can understand
"the tallest man" without knowing who the tallest man
is--but must know how to tell what the expression would refer to,
given certain information about the world (namely, the heights of all
the men in it).



These functions, or rules, are called (following Carnap (1947))
intensions. Possible worlds semantics is the view that contents are
intensions (and hence that characters are functions from contexts to
intensions, i.e. functions from contexts to functions from
circumstances of evaluation to a reference). (See figure 3.)



![diagram with text: link to extended description below](pws.gif)

Figure 3. [An
 extended description of figure 3
 is in the supplement.]




For discussion of the application of the framework of possible world
semantics to natural language, see David Lewis (1970). The intension
of a sentence--i.e., the proposition that sentence expresses, on
the present view--will then be a function from worlds to
truth-values. In particular, it will be that function which returns
the truth-value true for every world with respect to which that
sentence is true, and false otherwise. The intension of a simple
predicate like "is red" will be a function from worlds to
the function from objects to truth-values which, for each world,
returns the truth-value true if the thing in question is red, and
returns the truth-value false otherwise. In effect, possible worlds
semantics takes the meanings of expressions to be functions from
worlds to the values which would be assigned by a theory of reference
to those expressions at the relevant world: in that sense, intensions
are a kind of "extra layer" on top of the theory of
reference.



This extra layer promises to solve the problem posed by
non-extensional contexts, as illustrated by the example of
"cordate" and "renate" in
 (7) and (8).
 Our worry was that, since these expressions have the same reference,
if meaning just is reference, then it seems that any pair of sentences
which differ only in the substitution of these expressions must have
the same truth-value. But (7) and (8) are such a pair of sentences,
and needn't have the same truth-value. The proponent of possible
worlds semantics solves this problem by identifying the meaning of
these expressions with their intension rather than their reference,
and by pointing out that "cordate" and
"renate", while they share a reference, seem to have
different intensions. After all, even if in our world every creature
with a heart is a creature with a kidney (and vice versa), it seems
that the world could have been such that some creatures had a heart
but not a kidney. Since with respect to that circumstance of
evaluation the terms will differ in reference, their
intensions--which are just functions from circumstances of
evaluations to referents--must also differ. Hence possible worlds
semantics leaves room for (7) and (8) to differ in truth value, as
they manifestly can.



The central problem facing possible worlds semantics, however,
concerns sentences of the same form as
 (7) and (8):
 sentences which ascribe propositional attitudes, like beliefs, to
subjects. To see this problem, we can begin by asking: according to
possible worlds semantics, what does it take for a pair of sentences
to have the same content (i.e., express the same proposition)? Since
contents are intensions, and intensions are functions from
circumstances of evaluation to referents, it seems that two sentences
have the same content, according to possible worlds semantics, if they
have the same truth-value with respect to every circumstance of
evaluation. In other words, two sentences express the same proposition
if and only if it is impossible for them to differ in truth-value.



The problem is that there are sentences which have the same
truth-value in every circumstance of evaluation, but seem to differ in
meaning. Consider, for example


* (13)
\(2+2=4\).
* (14) There
are infinitely many prime numbers.



(13) and (14) are are both, like other truths of mathematics,
necessary truths. Hence (13) and (14) have the same intension and,
according to possible worlds semantics, must have the same
content.



But this is highly counterintuitive. (13) and (14) certainly seem to
say different things. The problem (just as with
 (5) and (6))
 can be sharpened by embedding these sentences in propositional
attitude ascriptions:


* (15) John believes that
*\(\mathit{2+2=4}\)*.
* (16) John believes
that *there are infinitely many prime numbers*.



As we have just seen, the proponent of possible worlds semantics must
take the italic sentences, (13) and (14), to have the same content;
hence, it seems, the proponent of possible worlds semantics must take
(15) and (16) to be a pair of sentences which differ only in the
substitution of expressions with the same content. But then it seems
that the proponent of possible worlds semantics must take this pair of
sentences to express the same proposition, and have the same
truth-value; but (15) and (16) (like
 (7) and (8))
 seem to differ in truth-value, and hence seem not to express the same
proposition. For an influential extension of this argument, see Soames
(1988).



For attempts to reply to the argument from within the framework of
possible worlds semantics, see among other places Stalnaker (1984) and
Yalcin (2018); for
discussion of a related approach to semantics which aims to avoid
these problems, see
 situations in natural language semantics (see entry).
 Another option is to invoke impossible as well as possible worlds;
one might then treat propositions as sets of worlds, which may or may
not be possible. If there is an impossible world in which there are
only finitely many primes but in which 2+2=4, that would promise to
give us the resources to distinguish between the set of worlds in
which
 (13)
 is true and the set of worlds in which
 (14)
 is true, and hence to explain the difference in truth-value between
 (15) and (16).
 For an overview of issues involving impossible worlds, see Nolan
(2013).


#### 2.1.6 Russellian semantics



What we need, then, is an approach to semantics which can explain how
sentences like
 (13) and (14),
 and hence also
 (15) and (16),
 can express different propositions. That is, we need a view of
propositions which makes room for the possibility that a pair of
sentences can be true in just the same circumstances but nonetheless
have genuinely different contents.



A natural thought is that
 (13) and (14)
 have different contents because they are about different things; for
example,
 (14)
 makes a general claim about the set of prime numbers whereas
 (13)
 is about the relationship between the numbers 2 and 4. One might want
our semantic theory to be sensitive to such differences: to count two
sentences as expressing different propositions if they are have
different subject matters, in this sense. One way to secure this
result is to think of the contents of subsentential expressions as
components of the proposition expressed by the sentence as a whole.
Differences in the contents of subsentential expressions would then be
sufficient for differences in the content of the sentence as a whole;
so, for example, since (14) but not (13) contains an expression which
refers to prime numbers, these sentences will express different
propositions.



Proponents of this sort of view think of propositions as
*structured*: as having constituents which include the meanings
of the expressions which make up the sentence expressing the relevant
proposition. (See, for more discussion, the entry on
 structured propositions.)
 One important question for views of this sort is: what does it mean
for an abstract object, like a proposition, to be structured, and have
constituents? But this question would take us too far afield into
metaphysics (see
 SS2.3.3
 below for a brief discussion). The fundamental *semantic*
question for proponents of this sort of structured proposition view
is: what sorts of things are the constituents of propositions?



The answer to this question given by a proponent of *Russellian
propositions* is: objects, properties, relations, and functions.
(The view is called "Russellianism" because of its
resemblance to the view of content defended in Chapter IV of Russell
1903.) So described, Russellianism is a general view about what sorts
of things the constituents of propositions are, and does not carry a
commitment to any views about the contents of particular types of
expressions. However, most Russellians also endorse a particular view
about the contents of proper names which is known as
*Millianism*: the view that the meaning of a simple proper name
is the object (if any) for which it stands.



Russellianism has much to be said for it. It not only solves the
problems with possible worlds semantics discussed above, but fits well
with the intuitive idea that the function of names is to single out
objects, and the function of predicates is to (what else?) predicate
properties of those objects.



However, Millian-Russellian semantic theories also face some problems.
Some of these are metaphysical in nature, and are based on the premise
that propositions which have objects among their constituents cannot
exist in circumstances in which those objects do not exist. (For
discussion, see the entry on
 singular propositions.)
 Of the semantic objections to Millian-Russellian semantics, two are
especially important.



The first of these problems involves the existence of *empty
names*: names which have no referent. It is a commonplace that
there are such names; an example is "Vulcan", the name
introduced for the planet between Mercury and the sun which was
causing perturbations in the orbit of Mercury. Because the
Millian-Russellian says that the content of a name is its referent,
the Millian-Russellian seems forced into saying that empty names lack
a content. But this is surprising; it seems that we can use empty
names in sentences to express propositions and form beliefs about the
world. The Millian-Russellian owes some explanation of how this is
possible, if such names genuinely lack a content. An excellent
discussion of this problem from a Millian point of view is provided in
Braun (1993).



Perhaps the most important problem facing Millian-Russellian views,
though, is Frege's puzzle. Consider the sentences


* (17) Clark
Kent is Clark Kent.
* (18) Clark
Kent is Superman.



According to the Millian-Russellian, (17) and (18) differ only in the
substitution of expressions with have the same content: after all,
"Clark Kent" and "Superman" are proper names
which refer to the same object, and the Millian-Russellian holds that
the content of a proper name is the object to which that name refers.
But this is a surprising result. These sentences seem to differ in
meaning, because (17) seems to express a trivial, obvious claim,
whereas (18) seems to express a non-trivial, potentially informative
claim.



This sort of objection to Millian-Russellian views can (as above) be
strengthened by embedding the intuitively different sentences in
propositional attitude ascriptions, as follows:


* (19) Lois
believes that Clark Kent is *Clark Kent*.
* (20) Lois
believes that Clark Kent is *Superman*.



The problem posed by (19) and (20) for Russellian semantics is
analogous to the problem posed by
 (15) and (16)
 for possible worlds semantics. Here, as there, we have a pair of
belief ascriptions which seem as though they could differ in
truth-value despite the fact that these sentences differ only with
respect to expressions counted as synonymous by the relevant semantic
theory.



Russellians have offered a variety of responses to Frege's
puzzle. Many Russellians think that our intuition that sentences like
 (19)
 and
 (20)
 can differ in truth-value is based on a mistake. This mistake might
be explained at least partly in terms of a confusion between the
proposition semantically expressed by a sentence in a context and the
propositions speakers would typically use that sentence to
pragmatically convey (Salmon 1986; Soames 2002), or in terms of the
fact that a single proposition may be believed under several
"propositional guises" (again, see Salmon 1986), or in
terms of a failure to integrate pieces of information stored using
distinct mental representations (Braun & Saul
 2002).[3]
 Alternatively, a Russellian might try to make room for (19) and (20)
to genuinely differ in truth-value by giving up the idea that
sentences which differ only in the substitution of proper names with
the same content must express the same proposition (Taschek 1995, Fine
2007).


#### 2.1.7 Fregean semantics



However, these are not the only responses to Frege's puzzle.
Just as the Russellian responded to the problem posed by
 (15) and (16)
 by holding that two sentences with the same intension can differ in
meaning, one might respond to the problem posed by
 (19)
 and
 (20)
 by holding that two names which refer to the same object can differ
in meaning, thus making room for (19) and (20) to differ in
truth-value. This is to endorse a Fregean response to Frege's
puzzle, and to abandon the Russellian approach to semantics (or, at
least, to abandon Millian-Russellian semantics).



Fregeans, like Russellians, think of the proposition expressed by a
sentence as a structured entity with constituents which are the
contents of the expressions making up the sentence. But Fregeans,
unlike Russellians, do not think of these propositional constituents
as the objects, properties, and relations for which these expressions
stand; instead, Fregeans think of the contents as modes of
presentation, or ways of thinking about, objects, properties, and
relations. The standard term for these modes of presentation is
*sense*. (As with "intension", "sense"
is sometimes also used as a synonym for "content". But, as
with "intension", it avoids confusion to restrict
"sense" for "content, as construed by Fregean
semantics". It is then controversial whether there are such
things as senses, and whether they are the contents of expressions.)
Frege explained his view of senses with an analogy:



> 
> 
> The reference of a proper name is the object itself which we designate
> by its means; the idea, which we have in that case, is wholly
> subjective; in between lies the sense, which is indeed no longer
> subjective like the idea, but is yet not the object itself. The
> following analogy will perhaps clarify these relationships. Somebody
> observes the Moon through a telescope. I compare the Moon itself to
> the reference; it is the object of the observation, mediated by the
> real image projected by the object glass in the interior of the
> telescope, and by the retinal image of the observer. The former I
> compare to the sense, the latter is like the idea or experience. The
> optical image in the telescope is indeed one-sided and dependent upon
> the standpoint of observation; but it is still objective, inasmuch as
> it can be used by several observers. At any rate it could be arranged
> for several to use it simultaneously. But each one would have his own
> retinal image. (Frege 1892 [1960])
> 
> 
> 



Senses are then objective, in that more than one person can express
thoughts with a given sense, and correspond many-one to objects. Thus,
just as Russellian propositions correspond many-one to intensions,
Fregean propositions correspond many-one to Russellian propositions.
This is sometimes expressed by the claim that Fregean contents are
more *fine-grained* than Russellian contents (or
intensions).



Indeed, we can think of our three classical semantic theories, along
with the theory of reference, as related by this kind of many-one
relation, as illustrated by the chart below:



![diagram: link to extended description below](levels.jpg)

Figure 4. [An
 extended description of figure 4
 is in the supplement.]




The principal argument for Fregean semantics (which also motivated
Frege himself) is the neat solution the view offers to Frege's
puzzle: the view says that, in cases like
 (19)
 and
 (20)
 in which there seems to be a difference in content, there really is a
difference in content: the names share a reference, but differ in
their sense, because they differ in their mode of presentation of
their shared reference.



The principal challenge for Fregeanism is the challenge of giving a
non-metaphorical explanation of the nature of sense. This is a problem
for the Fregean in a way that it is not for the possible worlds
semanticist or the Russellian since the Fregean, unlike these two,
introduces a new class of entities to serve as meanings of expressions
rather than merely appropriating an already recognized sort of
entity--like a function, or an object, property, or
relation--to serve this
 purpose.[4]



A first step toward answering this challenge is provided by a
criterion for telling when two expressions differ in meaning, which
might be stated as follows. In his 1906 paper, "A Brief Survey
of My Logical Doctrines", Frege seems to endorse the following
criterion:



> 
> *Frege's criterion of difference for senses*
>   
> 
> Two sentences *S* and *S\** differ in sense if and only if
> some rational agent who understood both could, on reflection, judge
> that *S* is true without judging that *S\** is true.
> 



One worry about this formulation concerns the apparent existence of
pairs of sentences, like "If Obama exists, then
Obama=Obama" and "If McCain exists, McCain=McCain"
which are such that any rational person who understands both will take
both to be true. These sentences seem intuitively to differ in
content--but this is ruled out by the criterion above. One idea
for getting around this problem would be to state our criterion of
difference for senses of expressions in terms of differences which
result from substituting one expression for another:



> 
> Two expressions *e* and *e\** differ in sense if and only
> if there are a pair of sentences, *S* and *S\** which (i)
> differ only in the substitution of *e* for *e*\* and (ii) are
> such that some rational agent who understood both could, on
> reflection, judge that *S* is true without judging that *S\**
> is true.
> 



This version of the criterion has Frege's formulation as a
special case, since sentences are, of course, expressions; and it
solves the problem with obvious truths, since it seems that
substitution of sentences of this sort can change the truth value of a
propositional attitude ascription. Furthermore, the criterion delivers
the wanted result that coreferential names like "Superman"
and "Clark Kent" differ in sense, since a rational,
reflective agent like Lois Lane could think that
 (17)
 is true while withholding assent from
 (18).



But even if this tells us when names differ in sense, it does not
quite tell us what the sense of a name *is*. Here is one
initially plausible way of explaining what the sense of a name is. We
know that, whatever the content of a name is, it must be something
which determines as a reference the object for which the name stands;
and we know that, if Fregeanism is true, this must be something other
than the object itself. A natural thought, then, is that the content
of a name--its sense--is some condition which the referent
of the name uniquely satisfies. Coreferential names can differ in
sense because there is always more than one condition which a given
object uniquely satisfies. (For example, Superman/Clark Kent uniquely
satisfies both the condition of being the superhero Lois most admires,
and the newspaperman she least admires.) Given this view, it is
natural to then hold that names have the same meanings as *definite
descriptions*--phrases of the form "the
so-and-so". After all, phrases of this sort seem to be designed
to pick out the unique object, if any, which satisfies the condition
following the "the". (For more discussion, see entry on
 descriptions.)
 This Fregean view of names is called *Fregean
descriptivism*.



However, as Saul Kripke argued in *Naming and Necessity*,
Fregean descriptivism faces some serious problems. Here is one of the
arguments he gave against the view, which is called the *modal
argument*. Consider a name like "Aristotle", and
suppose for purposes of exposition that the sense I associate with
that name is the sense of the definite description "the greatest
philosopher of antiquity". Now consider the following pair of
sentences:


* (21)
Necessarily, if Aristotle exists, then Aristotle is
*Aristotle*.
* (22)
Necessarily, if Aristotle exists, then Aristotle is *the greatest
philosopher of antiquity*.



If Fregean descriptivism is true, and "the greatest philosopher
of antiquity" is indeed the description I associate with the
name "Aristotle", then it seems that (21) and (22) must be
a pair of sentences which differ only via the substitution of
expressions (the italic ones) with the same content. If this is right,
then (21) and (22) must express the same proposition, and have the
same truth-value. But this seems to be a mistake; while (21) appears
to be true (Aristotle could hardly have failed to be himself), (22)
appears to be false (perhaps Aristotle could have been a shoemaker
rather than a philosopher; or perhaps if Plato had worked a bit
harder, he rather than Aristotle could have been the greatest
philosopher of antiquity).



An important precursor to Kripke's arguments against Fregean
descriptivism is Marcus (1961), which argues that names are
"tags" for objects rather than abbreviated descriptions.
Fregean descriptivists have given various replies to Kripke's
modal and other arguments; see especially Plantinga (1978), Dummett
(1981), and Sosa (2001). For rejoinders to these Fregean replies, see
Soames (1998, 2002) and Caplan (2005). For a defense of a view of
descriptions which promises a reply to the modal argument, see
Rothschild (2007). For a brief sketch of Kripke's other
arguments against Fregean descriptivism, see
 names, SS2.4.



Kripke's arguments provide a strong reason for Fregeans to deny
Fregean descriptivism, and hold instead that the senses of proper
names are not the senses of any definite description associated with
those names by speakers. The main problem for this sort of
*non-descriptive Fregeanism* is to explain what the sense of a
name might be such that it can determine the reference of the name, if
it is not a condition uniquely satisfied by the reference of the name.
Non-descriptive Fregean views were defended in McDowell (1977) and
Evans (1981). The most sophisticated and well-developed version of the
view is a kind of blend of Fregean semantics and possible worlds
semantics. This is the epistemic two-dimensionalist approach to
semantics which has been developed by David Chalmers. See Chalmers
(2004,2006).



Three other problems for Fregean semantics are worth mentioning. The
first is the problem of whether the Fregean can give an adequate
treatment of indexical expressions. A classic argument that the
Fregean cannot is given in Perry (1977); for a Fregean reply, see
Evans (1981).



The first calls into question the Fregean's claim to have
provided a plausible solution to Frege's puzzle. The Fregean
resolves instances of Frege's puzzle by positing differences in
sense to explain apparent differences in truth-value. But this sort of
solution, if pursued generally, seems to lead to the surprising result
that no two expressions can have the same content. For consider a pair
of expressions which really do seem to have the same content, like
"catsup" and "ketchup". (The example, as well
as the argument to follow, is borrowed from Salmon 1990.) Now consider
Bob, a confused condiment user, who thinks that the tasty red
substance standardly labeled "catsup" is distinct from the
tasty red substance standardly labeled "ketchup", and
consider the following pair of sentences:


* (23) Bob
believes that catsup is *catsup*.
* (24) Bob
believes that catsup is *ketchup*.



(23) and (24) seem quite a bit like
 (19)
 and
 (20):
 these each seem to be pairs of sentences which differ in truth-value,
despite differing only in the substitution of the italic expressions.
So, for consistency, it seems that the Fregean should explain the
apparent difference in truth-value between (23) and (24) in just the
way he explains the apparent difference in truth-value between (19)
and (20): by positing a difference in meaning between the italic
expressions. But, first, it is hard to see how expressions like
"catsup" and "ketchup" could differ in
meaning; and, second, it seems that an example of this sort could be
generated for any alleged pair of synonymous expressions. (A closely
related series of examples is developed in much more detail in Kripke
1979.)



The example of "catsup" and "ketchup" is
related to a second worry for the Fregean, which is the reverse of the
Fregean's complaint about Russellian semantics: a plausible case
can be made that Frege's criterion of difference for sense
slices contents too finely, and draws distinctions in content where
there are none. One way of developing this sort of argument involves
(again) propositional attitude ascriptions. It seems plausible that if
I utter a sentence like "Hammurabi thought that Hesperus was
visible only in the morning", what I say is true if and only if
one of Hammurabi's thoughts has the same content as does the
sentence "Hesperus was visible only in the morning", as
used by me. On a Russellian view, this places a reasonable constraint
on the truth of the ascription; it requires only that Hammurabi
believe of a certain object that it instantiates the property of being
visible in the morning. But on a Fregean view, this sort of view of
attitude ascriptions would require that Hammurabi thought of the
planet Venus under the same mode of presentation as I attach to the
term "Hesperus". This seems implausible, since it seems
that I can truly report Hammurabi's beliefs without knowing
anything about the mode of presentation under which he thought of the
planets. (For a recent attempt to develop a Fregean semantics for
propositional attitude ascriptions which avoids this sort of problem
by integrating aspects of a Russellian semantics, see Chalmers
(2011).)


### 2.2 Alternatives to Classical Semantic Theories



Classical semantic theories, however, are not the only game in town.
This section lays out the basics of five alternatives to classical semantic
theorizing.


#### 2.2.1 Davidsonian semantics



One kind of challenge to classical semantics attacks the idea that the
job of a semantic theory is to systematically pair expressions with
the entities which are their meanings. Wittgenstein was parodying just
this idea when he wrote 



> 
> 
> You say: the point isn't the word, but its meaning, and you
> think of the meaning as a thing of the same kind as the word, though
> also different from the word. Here the word, there the meaning. The
> money, and the cow that you can buy with it. (Wittgenstein 1953,
> SS120)
> 
> 
> 



While Wittgenstein himself did not think that systematic theorizing
about semantics was possible, this anti-theoretical stance has not
been shared by all subsequent philosophers who share his aversion to
"meanings as entities". A case in point is Donald
Davidson. Davidson thought that semantic theory should take the form
of a theory of truth for the language of the sort which Alfred Tarski
showed us how to construct (see Tarski 1944 and entry on
 Tarski's truth definitions).



For our purposes, it will be convenient to think of a Tarskian truth
theory as a variant on the sorts of theories of reference introduced
in
 SS2.1.1.
 Recall that theories of reference of this sort specified, for each
proper name in the language, the object to which that name refers, and
for every simple predicate in the language, the set of things which
satisfy that predicate. If we then consider a sentence which combines
a proper name with such a predicate, like



> 
> 
> Amelia sings
> 
> 
> 



the theory tells us what it would take for that sentence to be true:
it tells us that this sentence is true if and only if the object to
which "Amelia" refers is a member of the set of things
which satisfy the predicate "sings"--i.e., the set of
things which sing. So we can think of a full theory of reference for
the language as implying, for each sentence of this sort, a
*T-sentence* of the form



> 
> 
> "Amelia sings" is *T* (in the language) if and only
> if Amelia sings.
> 
> 
> 



Suppose now that we expand our theory of reference so that it implies
a T-sentence of this sort for every sentence of the language, rather
than just for simple sentences which result from combining a name and
a monadic predicate. We would then have a Tarskian truth theory for
our language. Tarski's idea was that such a theory would define
a truth predicate ("*T*") for the language; Davidson,
by contrast, thought that we find in Tarskian truth theories
"the sophisticated and powerful foundation of a competent theory
of meaning" (Davidson 1967).



This claim is puzzling: why should a a theory which issues
T-sentences, but makes no explicit claims about meaning or content,
count as a *semantic* theory? Davidson's answer was that
knowledge of such a theory would be sufficient to understand the
language. If Davidson were right about this, then he would have a
plausible argument that a semantic theory could take this form. After
all, it is plausible that someone who understands a language knows the
meanings of the expressions in the language; so, if knowledge of a
Tarskian truth theory for the language were sufficient to understand
the language, then knowledge of what that theory says would be
sufficient to know all the facts about the meanings of expressions in
the language, in which case it seems that the theory would state all
the facts about the meanings of expressions in the language.



One advantage of this sort of approach to semantics is its parsimony:
it makes no use of the intensions, Russellian propositions, or Fregean
senses assigned to expressions by the propositional semantic theories
discussed above. Of course, as we saw above, these entities were
introduced to provide a satisfactory semantic treatment of various
sorts of linguistic constructions, and one might well wonder whether
it is possible to provide a Tarskian truth theory of the sort sketched
above for a natural language without making use of intensions,
Russellian propositions, or Fregean senses. The Davidsonian program
obviously requires that we be able to do this, but it is still very
much a matter of controversy whether a truth theory of this sort can
be constructed. Discussion of this point is beyond the scope of this
entry; one good way into this debate is through the debate about
whether the Davidsonian program can provide an adequate treatment of
propositional attitude ascriptions. See the discussion of the
paratactic account and interpreted logical forms in the entry on
 propositional attitude reports.
 (For Davidson's initial treatment of attitude ascriptions, see
Davidson 1968; for further discussion see, among other places, Burge
1986; Schiffer 1987; Lepore and Loewer 1989; Larson and Ludlow 1993;
Soames 2002.)



Let's set this aside, and assume that a Tarskian truth theory of
the relevant sort can be constructed, and ask whether, given this
supposition, this sort of theory would provide an adequate semantics.
There are two fundamental reasons for thinking that it would not, both
of which are ultimately due to Foster (1976). Larson and
Segal (1995) call these the *extension problem* and the
*information problem*.



The extension problem stems from the fact that it is not enough for a
semantic theory whose theorems are T-sentences to yield true theorems;
the T-sentence



> 
> 
> "Snow is white" is *T* in English iff grass is
> green.
> 
> 
> 



is true, but tells us hardly anything about the meaning of "Snow
is white". Rather, we want a semantic theory to entail, for each
sentence of the object language, exactly one *interpretive*
T-sentence: a T-sentence such that the sentence used on its right-hand
side gives the meaning of the sentence mentioned on its left-hand
side. Our theory must entail *at least one* such T-sentence for
each sentence in the object language because the aim is to give the
meaning of each sentence in the language; and it must entail *no
more than one* because, if the theory had as theorems more than
one T-sentence for a single sentence *S* of the object language,
an agent who knew all the theorems of the theory would not yet
understand *S*, since such an agent would not know which of the
T-sentences which mention *S* was interpretive.



The problem is that it seems that any theory which implies at least
one T-sentence for every sentence of the language will also imply more
than one T-sentence for every sentence in the language. For any
sentences *p*, *q*, if the theory entails a T-sentence



> 
> 
> *S* is *T* in *L* iff *p*,
> 
> 
> 



then, since *p* is logically equivalent to \(p \amp \nsim(q \amp
\nsim q)\), the theory will also entail the T-sentence



> 
> 
> *S* is *T* in *L* iff \(p \amp \nsim(q \amp \nsim
> q)\),
> 
> 
> 



which, if the first is interpretive, won't be. But then the
theory will entail at least one non-interpretive T-sentence, and
someone who knows the theory will not know which of the relevant
sentences is interpretive and which not; such a person therefore would
not understand the language.



The information problem is that, even if our semantic theory entails
all and only interpretive T-sentences, it is not the case that
knowledge of what is said by these theorems would suffice for
understanding the object language. For, it seems, I can know what is
said by a series of interpretive T-sentences without knowing that they
are interpretive. I may, for example, know what is said by the
interpretive T-sentence



> 
> 
> "Londres est jolie" is *T* in French iff London is
> pretty
> 
> 
> 



but still not know the meaning of the sentence mentioned on the
left-hand side of the T-sentence. The truth of what is said by this
sentence, after all, is compatible with the sentence used on the
right-hand side being materially equivalent to, but different in
meaning from, the sentence mentioned on the left. This seems to
indicate that knowing what is said by a truth theory of the relevant
kind is not, after all, sufficient for understanding a language. (For
replies to these criticisms, see Davidson (1976), Larson and Segal
(1995) and Kolbel (2001); for criticism of these replies, see
Soames (1992) and Ray (2014). For a reply to the latter, see
Kirk-Giannini and Lepore (2017).)


#### 2.2.2 Internalist semantics



The Davidsonian, on one reading, diagnoses the mistake of classical
semantics in its commitment to a layer of content which goes beyond a
theory of reference. A different alternative to classical semantics
departs even more radically from that tradition, by denying that
mind-world reference relations should play any role in semantic
theorizing.



This view is sometimes called "internalist semantics" by
contrast with views which locate the semantic properties of
expressions in their relation to elements of the external world. This
internalist approach to semantics is associated with the work of Noam
Chomsky (see especially Chomsky 2000).



It is easy to say what this approach to semantics denies. The
internalist denies an assumption common to all of the approaches
discussed so far: the assumption that in giving the content of an
expression, we are primarily specifying something about that
expression's relation to things in the world which that
expression might be used to say things about. According to the
internalist, expressions as such don't bear any semantically
interesting relations to things in the world; names don't, for
example, *refer* to the objects with which one might take them
to be associated; predicates don't have extensions; sentences
don't have truth conditions. On this sort of view, we can use
sentences to say true or false things about the world, and can use
names to refer to things; but this is just one thing we can do with
names and sentences, and is not a claim about the meanings of those
expressions.



So what are meanings, on this view? The most developed answer to this
question is given in Pietroski (2018), according to which
"meanings are instructions for how to build concepts of a
special sort" (2018: 36). By "concepts", Pietroski
means mental representations of a certain kind. So the meaning of an
expression is an instruction to form a certain sort of mental
representation.



On this kind of view, while concepts may have extensions, expressions
of natural languages do not. So this approach rejects not just the
details but the foundation of the classical approach to semantics
described above.



One way to motivate an approach of this kind focuses on the ubiquity
of the phenomenon of polysemy in natural languages. As Pietroski says,




> 
> 
> We can use "line" to speak of Euclidean lines, fishing
> lines, telephone lines, waiting lines, lines in faces, lines of
> thought, etc. We can use "door" to access a concept of
> certain impenetrable objects, or a concept of certain spaces that can
> be occupied by such objects. (2018: 5) 
> 
> 
> 



The defender of the view that expressions have meanings which
determine extensions seems forced to say that "line" and
"door" are homophonous expressions, like
"bank". But that seems implausible; when one uses the
expressions "fishing line" and "line of
thought" one seems to be using "line" in
recognizably the same sense. (This is a point of contrast with
standard examples of homophony, as when uses "bank" once
to refer to a financial institution and then later to refer to the
side of a river.) The internalist, by contrast, is not forced into
treating these as cases of homophony; he can say that the meaning of
"line" is an instruction to fetch one of a family of
concepts.



For defenses and developments of internalist approaches to semantics,
see McGilvray (1998), Chomsky (2000), and Pietroski (2003, 2005,
2018).


#### 2.2.3 Inferentialist semantics



Internalist semantics can be understood as denying that classical
semantic assumption that a semantic theory should assign truth
conditions to sentences. Another alternative to classical semantics
does not deny that assumption, but does deny that truth conditions
should play the fundamental role in semantics that classical semantics
give to them.



This alternative is inferentialist semantics. The difference between
classical and inferentialist semantics is nicely put by Robert
Brandom:



> 
> 
> The standard way [of classical semantics] is to assume that one has a
> prior grip on the notion of truth, and use it to explain what good
> inference consists in. ... [I]nferentialist pragmatism reverses
> this order of explanation ... It starts with a practical
> distinction between good and bad inferences, understood as a
> distinction between appropriate and inappropriate doings, and goes on
> to understand talk about truth as talk about what is preserved by the
> good moves. (Brandom 2000: 12)
> 
> 
> 



The classical semanticist begins with certain language-world
representational relations, and uses these to explain the truth
conditions of sentences; we can then go on to use these truth
conditions to explain the difference between good and bad inferences.
The inferentialist, by contrast, begins with the distinction between
good and bad inferences, and tries to explain the representational
relations which the classical semanticist takes as (comparatively)
basic in inferentialist terms. (I say "comparatively
basic" because the classical semanticist might go on to provide
a reductive explanation of these representational relations, and the
inferentialist might go on to provide a reductive explanation of the
distinction between good and bad inferences.



As Brandom also emphasizes, the divergence between the classical and
inferentialist approaches to semantics arguably brings with it a
divergence on two other fundamental topics.



The first is the relative explanatory priority of the semantic
properties of sentences, on the one hand, and subsentential
expressions, on the other. It is natural for the classical semanticist
to think that the representational relations between subsentential
expressions and their semantic contents can be explained independently
of the representational properties of sentences (i.e., their truth
conditions); the latter can thus be explained in terms of the former.
For the inferentialist, on the other hand, the semantic properties of
sentences must come first, because inferential relations hold between
sentences but not between subsentential expressions. (One cannot, for
example, infer one name from another.) So the inferentialist will not
explain the semantic properties of, for example, singular terms in
terms of representational relations between those singular terms and
items in the world; rather, she will explain what is distinctive of
singular terms in terms of their role in certain kinds of inferences.
(To see how this strategy might work, see Brandom 2000: Ch. 4.)



The second is the relative explanatory priority of the semantic
properties of individual sentences, on the one hand, and the semantic
relations between sentences on the other. The classical semanticist
can, so to speak, explain the meanings of sentences one by one; there
is no difficulty in explaining the meaning of a sentence without
mentioning other sentences. By contrast, according to the
inferentialist,



> 
> 
> if the conceptual content expressed by each sentence or word is
> understood as essentially consisting in its inferential relations
> (broadly construed) or articulated by its inferential relations
> (narrowly construed), then one must grasp many such contents in order
> to grasp any. (Brandom 2000: 29)
> 
> 
> 



This is sometimes called a holist approach to semantics. For
discussions of the pros and cons of this kind of view, see the entry
on
 meaning holism.



For book length defenses of inferentialism, see Brandom (1994) and
Brandom (2000). Important precursors include Wittgenstein (1953) and
Sellars (1968); see also the entries on
 Ludwig Wittgenstein
 and
 Wilfrid Sellars.
 For a classic objection to inferentialism, see Prior (1960). For a
discussion of a prominent approach within the inferentialist
tradition, see the entry on
 proof-theoretic semantics.


#### 2.2.4 Dynamic semantics



In laying out the various versions of classical semantics, we said a
lot about sentences. By comparison, we said hardly anything about
conversations, or discourses. This is no accident; classical
approaches to semantics typically think of properties of conversations
or discourses as explicable in terms of explanatorily prior semantic
properties of sentences (even if classical semanticists do often take
the semantic contents of sentences to be sensitive to features of the
discourse in which they occur).



Dynamic semantics is, to a first approximation, an approach to
semantics which reverses these explanatory priorities. (The sorts of
classical theories sketched above are, by contrast, called
"static" semantic theories.) On a dynamic approach, a
semantic theory does not aim primarily to deliver a pairing of
sentences with propositions which then determine the sentence's
truth conditions. Rather, according to these dynamic approaches to
semantics, the semantic values of sentences are rather "context
change potentials"--roughly, instructions for updating the
context, or discourse.



In a dynamic context, many of the questions posed above about how best
to understand the nature of semantic contents show up instead as
questions about how best to understand the nature of contexts and
context change potentials. It is controversial not just whether a
dynamic or static approach to semantics is likely to be more fruitful,
but also what exactly the distinction between dynamic and static
systems comes to. (For discussion of the latter question, see
Rothschild & Yalcin 2016.)



The relationship between dynamic semantics and classical semantics is
different than the relationship between the latter and the other
alternatives to classical semantics that I've discussed. The
other alternatives to classical semantics reject some core feature of
classical semantics--for example, the assignments of entities as
meanings, or the idea that meaning centrally involves word-world
relations. By contrast, dynamic semantics can be thought of as a kind
of extension or generalization of classical semantics, which can
employ modified versions of much of the same theoretical
machinery.



Foundational works in this tradition include Irene Heim's file
change semantics (1982)
and Hans Kamp's
 discourse representation theory (see entry).
 For more details on different versions of this alternative to
classical semantics, see the entry on
 dynamic semantics.
 For critical discussion of the motivations for dynamic semantics, see
Karen Lewis (2014). For discussion of the extent to which dynamic and
static approaches are really in competition, see Stojnic
(2019).


#### 2.2.5 Expressivist semantics



A final alternative to classical semantics differs from those
discussed in the preceding four subsections in two (related)
respects.



The first is that, unlike the other non-classical approaches,
expressivist semantics was originally not motivated by linguistic
considerations. Rather, it was developed in response to specifically
metaethical considerations. A number of philosophers held metaethical
views which made it hard for them to see how a classical semantic
treatment of sentences about ethics could be correct, and so developed
expressivism as an alternative treatment of these parts of
language.



This leads to a second difference between expressivist and our other
four alternatives to classical semantics. The latter are all
"global alternatives", in the sense that they propose
non-classical approaches to the semantics of all of a natural
language. By contrast, expressivists typically agree that classical
semantics (or one of the other non-expressivist alternatives to it
discussed in
 SSSS2.2.1-4)
 is correct for many parts of language; they just think that special
features of some parts of language require expressivist treatment.



One can think of many traditional versions of expressivism, which were
motivated by metaethical concerns, as involving two basic ideas.
First, we can explain the meaning of a mental state by saying what
mental state that sentence expresses. Second, the mental state
expressed by a sentence about ethics is different in kind from the
mental state expressed by a "factual" sentence.



Two follow up questions suggest themselves. One is about what
"expresses" means here; for one answer, see Gibbard
(1990). A second is about what the relevant difference in mental
states consists in. On many views, the mental states expressed by
non-ethical sentences are beliefs, whereas the mental states expressed
by ethical sentences are not. Different versions of expressivism
propose different candidates for the mental states which are expressed
by ethical sentences. Prominent candidates include exclamations (Ayer
1936), commands (Hare 1952), and plans (Gibbard 1990, 2003).



A classic problem for expressivist theories of the kind just sketched
comes from interactions between ethical and non-ethical bits of
language. This problem has come to be known as the Frege-Geach
problem, because a very influential version of the problem was posed
by Geach (1960, 1965). (A version of the problem is also independently
presented in Searle 1962.) In one of its versions, the problem comes
in two parts. First, whatever mental state expressivists take ethical
sentences to express will typically not be expressed by complex
sentences which embed the relevant ethical sentence. So even if




Lying is wrong.




expresses the mental state of planning not to lie, the same sentence
when embedded in the conditional




If lying is wrong, then what Jane did was wrong.




does not. After all, one can endorse this conditional without
endorsing a plan not to lie. So it seems that the expressivist must
say that "lying is wrong" means something different when
it occurs alone than it does when it occurs in the antecedent of a
conditional. The problem, though, is that if one takes that view it is
hard to see how it could follow from the above two sentences, as it
surely does, that




What Jane did was wrong.




For a discussion of solutions to this problem, and an influential
critique of expressivism, see Schroeder (2008).



Much recent work on expressivism is both less focused on the special
case of ethics, and more motivated by purely linguistic
considerations, than has often been the case traditionally. Examples
include discussions of expressivism about epistemic modality in Yalcin
(2007), about knowledge ascriptions in Moss (2013), and about
vagueness in MacFarlane (2016).


### 2.3 General Questions Facing Semantic Theories



As mentioned above, the aim of SS2 of this entry is to discuss
issues about the form which a semantic theory should take which are at
a higher level of abstraction than issues about the correct semantic
treatment of particular expression-types. (Also as mentioned above,
some of these may be found in the entries on
 conditionals,
 descriptions,
 names,
 propositional attitude reports, and
 tense and aspect.)
 But there are some general issues in semantics which, while more
general than questions about how, for example, the semantics of
adverbs should go, are largely (though not wholly) orthogonal to the
question of which of the frameworks for semantic theorizing laid out
in
 SS2.1-2
 should be adopted. The present subsection introduces a few of
these.


#### 2.3.1 How much context-sensitivity?



SS2.1.4 introduced the idea that
some expressions might be context-sensitive, or indexical. Within a
propositional semantics, we'd say that these expressions have
different contents relative to distinct contexts; but the phenomenon
of context-sensitivity is one which any semantic theory must
recognize. A very general question which is both highly important and
orthogonal to the above distinctions between types of semantic
theories is: How much context-sensitivity is there in natural
languages?



Virtually everyone recognizes a sort of core group of indexicals,
including "I", "here", and "now".
Most also think of demonstratives, like (some uses of)
"this" and "that", as indexicals. But whether
and how this list should be extended is a matter of controversy. Some
popular candidates for inclusion are:


* devices of quantification
* gradable adjectives
* alethic modals, including counterfactual conditionals
* "knows" and epistemic modals
* propositional attitude ascriptions
* "good" and other moral terms



Many philosophers and linguists think that one or more of these
categories of expressions are indexicals. Indeed, some think that
virtually every natural language expression is context-sensitive.



Questions about context-sensitivity are important, not just for
semantics, but for many areas of philosophy. And that is because some
of the terms thought to be context-sensitive are terms which play a
central role in describing the subject matter of other areas of
philosophy.



Perhaps the most prominent example here is the role that the view that
"knows" is an indexical has played in recent epistemology.
This view is often called "contextualism about knowledge";
and in general, the view that some term *F* is an indexical is
often called "contextualism about *F*". Contextualism
about knowledge is of interest in part because it promises to provide
a kind of middle ground between two opposing epistemological
positions: the skeptical view that we know hardly anything about our
surroundings, and the dogmatist view that we can know that we are not
in various Cartesian skeptical scenarios. (So, for example, the
dogmatist holds that I can know that I am not a brain in a vat which
is, for whatever reason, being made to have the series of experiences
subjectively indistinguishable from the experiences I actually have.)
Both of these positions can seem unappealing--skepticism because
it does seem that I can occasionally know, e.g., that I am sitting
down, and dogmatism because it's hard to see how I can rule out
the possibility that I am in a skeptical scenario subjectively
indistinguishable from my actual situation.



But the disjunction of these positions can seem, not just unappealing,
but inevitable; for the proposition that I am sitting entails that I
am not a brain in a vat, and it's hard to see--presuming
that I know that this entailment holds--how I could know the
former without thereby being in a position to know the latter. The
contextualist about "knows" aims to provide the answer:
the extension of "knows" depends on features of the
context of utterance. Perhaps--to take one among many possible
contextualist views--a pair of a subject and a proposition
*p* will be in the extension of "knows" relative to a
context only if that subject is able to rule out every possibility
which is both (i) inconsistent with *p* and (ii) salient in
*C*. The idea is that "I know that I am sitting down"
can be true in a normal setting, simply because the possibility that I
am a brain in a vat is not normally salient; but typically "I
know that I am not a brain in a vat" will be false, since
discussion of skeptical scenarios makes them salient, and (if the
skeptical scenario is well-designed) I will lack the evidence needed
to rule them out. See for discussion, among many other places, the
entry on
 epistemic contextualism,
 Cohen (1986), DeRose (1992), and David Lewis (1996).



Having introduced one important contextualist thesis, let's
return to the general question which faces the semantic theorist,
which is: How do we tell when an expression is context-sensitive?
Contextualism about knowledge, after all, can hardly get off the
ground unless "knows" really is a context-sensitive
expression. "I" and "here" wear their
context-sensitivity on their sleeves; but "knows" does
not. What sort of argument would suffice to show that an expression is
an indexical?



Philosophers and linguists disagree about the right answers to this
question. The difficulty of coming up with a suitable diagnostic is
illustrated by considering one intuitively plausible test, defended in
Chapter 7 of Cappelen & Lepore (2005). This test says that an
expression is an indexical iff it characteristically blocks
disquotational reports of what a speaker said in cases in which the
original speech and the disquotational report are uttered in contexts
which differ with respect to the relevant contextual parameter. (Or,
more cautiously, that this test provides evidence that a given
expression is, or is not, context-sensitive.)



This test clearly counts obvious indexicals as such. Consider
"I". Suppose that Mary utters




I am hungry.




One sort of disquotational report of Mary's speech would use the
very sentence Mary uttered in the complement of a "says"
ascription. So suppose that Sam attempts such a disquotational report
of what Mary said, and utters




Mary said that I am hungry.




The report is obviously false; Mary said that Mary is hungry, not that
Sam is. The falsity of Sam's report suggests that "I am
hungry" has a different content out of Mary's mouth than
out of Sam's; and this, in turn, suggests that "I"
has a different content when uttered by Mary than when uttered by Sam.
Hence, it suggests that "I" is an indexical.



It isn't just that this test gives the right result in many
cases; it's also that the test fits nicely with the plausible
view that an utterance of a sentence of the form "*A* said
that *S*" in a context *C* is true iff the content of
*S* in *C* is the same as the content of what the referent
of "*A*" said (on the relevant occasion).



The interesting uses of this test are not uses which show that
"I" is an indexical; we already knew that. The interesting
use of this test, as Cappelen and Lepore argue, is to show that many
of the expressions which have been taken to be indexicals--like
the ones on the list given above--are *not*
context-sensitive. For we can apparently employ disquotational reports
of the relevant sort to report utterances using quantifiers, gradable
adjectives, modals, "knows", etc. This test thus
apparently shows that no expressions beyond the obvious
ones--"I", "here", "now",
etc.--are genuinely context-sensitive.



But, as Hawthorne (2006) argues, naive applications of this test seem
to lead to unacceptable results. Terms for relative directions, like
"left", seem to be almost as obviously context-sensitive
as "I"; the direction picked out by simple uses of
"left" depends on the orientation of the speaker of the
context. But we can typically use "left" in disquotational
"says" reports of the relevant sort. Suppose, for example,
that Mary says



> 
> 
> The coffee machine is to the left.
> 
> 
> 



Sam can later truly report Mary's speech by saying



> 
> 
> Mary said that the coffee machine was to the left.
> 
> 
> 



despite the fact that Sam's orientation in the context of the
ascription differs from Mary's orientation in the context of the
reported utterance. Hence our test seems to lead to the absurd result
that "left" is not context-sensitive.



One interpretation of this puzzling fact is that our test using
disquotational "says" ascriptions is a bit harder to apply
than one might have thought. For, to apply it, one needs to be sure
that the context of the ascription really does differ from the context
of the original utterance *in the value of the relevant contextual
parameter*. And in the case of disquotational reports using
"left", one might think that examples like the above show
that the relevant contextual parameter is sometimes not the
orientation of the speaker, but rather the orientation of the subject
of the ascription at the time of the relevant utterance.



This is but one criterion for context-sensitivity. But discussion of
this criterion brings out the fact that the reliability of an
application of a test for context-sensitivity will in general not be
independent of the space of views one might take about the contextual
parameters to which a given expression is sensitive. For an
illuminating discussion of ways in which we might revise tests for
context-sensitivity using disquotational reports which are sensitive
to the above data, see Cappelen & Hawthorne (2009). For a critical
survey of other proposed tests for context-sensitivity, see Cappelen
& Lepore (2005: Part I).



This is just an introduction to one central issue concerning the
relationship between context and semantic content. A sampling of other
influential works on this topic includes Sperber and Wilson (1995),
Carston (2002), Recanati (2004, 2010), Bezuidenhout (2002), and the
essays in Stanley (2007).


#### 2.3.2 How many indices?



SS2.1.5 introduced the idea of an
expression determining a reference, relative to a context, with
respect to a particular circumstance of evaluation. But that
discussion left the notion of a circumstance of evaluation rather
underspecified. One might want to know more about what, exactly, these
circumstances of evaluation involve--and hence about what sorts
of things the reference of an expression can (once we've fixed a
context) vary with respect to.



One way to focus this question is to stay at the level of sentences,
and imagine that we have fixed on a sentence *S*, with a certain
character, and context *C*. If sentences express propositions
relative to contexts, then *S* will express some proposition
*P* relative to *C*. If the determination of reference in
general depends not just on character and context, but also on
circumstance, then we know that *P* might have different
truth-values relative to different circumstances of evaluation. Our
question is: exactly what must we specify in order to determine
*P*'s truth-value?



Let's say that an *index* is the sort of thing which, for
some proposition *P*, we must at least sometimes specify in order
to determine P's truth-value. Given this usage, we can think of
circumstances of evaluation--the things which play the
theoretical role outlined in
 SS2.1.5--as
 made up of indices.



The most uncontroversial candidate for an index is a world, because
most advocates of a propositional semantics think that propositions
can have different truth-values with respect to different possible
worlds. The main question is whether circumstances of evaluation need
contain any indices other than a possible world.



The most popular candidate for a second index is a time. The view that
propositions can have different truth-values with respect to different
times--and hence that we need a time index--is often called
"temporalism". The negation of temporalism is
eternalism.



The motivations for temporalism are both metaphysical and semantic. On
the metaphysical side, A-theorists about time (see the entry on
 time)
 think that corresponding to predicates like "is a child"
are A-series properties which a thing can have at one time, and lack
at another time. (Hence, on this view, the property corresponding to
"is a child" is not a property like *being a child in
2014*, since that is a property which a thing has permanently if
at all, and hence is a B-series rather than A-series property.) But
then it looks like the proposition expressed by "Violet is a
child"--which predicates this A-series property of
Violet--should have different truth-values with respect to
different times. And this is enough to motivate the view that we
should have an index for a time.



On the semantic side, as Kaplan (1989) notes, friends of the idea that
tenses are best modeled as operators have good reason to include a
time index in circumstances of evaluation. After all, operators
operate on contents, so if there are temporal operators, they will
only be able to affect truth-values if those contents can have
different truth-values with respect to different times.



A central challenge for the view that propositions can change
truth-value over time is whether the proponent of this view can make
sense of retention of propositional attitudes over time. For suppose
that I believe in 2014 that Violet is a child. Intuitively, I might
hold fixed all of my beliefs about Violet for the next 40 years,
without its being true, in 2054, that I have the obviously false
belief that Violet is still a child. But the temporalist, who thinks
of the proposition that Violet is a child as something which
incorporates no reference to a time and changes truth-value over time,
seems stuck with this result. Problems of this sort for temporalism
are developed in Richard (1981); for a response see Sullivan
(2014).



Motivations for eternalism are also both metaphysical and semantic.
Those attracted to B-theories of time will take propositions to have
their truth-values eternally, which makes inclusion of a time index
superfluous. And those who think that tenses are best modeled in terms
of quantification over times rather than using tense operators will,
similarly, see no use for a time index. For a defense of the
quantificational over the operator analysis of tense, see King
(2003).



Is there a case to be made for including any indices other than a
world and a time? There is; and this has spurred much of the recent
interest in relativist semantic theories. Relativist semantic theories
hold that our indices should include not just a world and (perhaps) a
time, but also a *context of assessment*. Just as propositions
can have different truth values with respect to different worlds, so,
on this view, they can vary in their truth depending upon features of
the conversational setting in which they are considered. (Though this
way of putting things assumes that the relativist should be a
"truth relativist" rather than a "content
relativist". See for discussion
Weatherson and Egan 2011: SS 2.3.)



The motivations for this sort of view can be illustrated by a type of
example whose importance is emphasized in Egan et al. (2005). Suppose
that, at the beginning of a murder investigation inquiry, I say



> 
> 
> The murderer might have been on campus at midnight.
> 
> 
> 



It looks like the proposition expressed by this sentence will be true,
roughly, if we don't know anything which rules out the murderer
having been on campus at midnight. But now suppose that more
information comes in, some of which rules out the murderer having been
on campus at midnight. At this point, it seems, I could truly say



> 
> 
> What I said was false--the murderer couldn't have been on
> campus at midnight.
> 
> 
> 



But this is puzzling. It is not puzzling that the sentence "The
murderer might have been on campus at midnight" could be true
when uttered in the first context but false when uttered in the second
context; that fact could be accommodated by any number of
contextualist treatments of epistemic modals, which would dissolve the
puzzle by saying that the sentence expresses different propositions
relative to the two contexts. The puzzle is that the truth of the
second sentence seems to imply that the proposition expressed by the
first--which we agreed was true relative to that context--is
false relative to the second context. Here we don't have (or
don't just have) sentences varying in truth-value depending on
context; we seem to have propositions varying in truth-value depending
on context. The relativist about epistemic modals takes appearance
here to be reality, and holds that, in addition to worlds (and maybe
times), propositions can sometimes differ in their truth-value
relative to contexts of assessment (roughly, the context in which the
proposition is being considered). (Note that it is not essential to
the case that the two contexts of assessment are at different times;
much the same intuitions can be generated by considering cases of
"eavesdropping", in which one party overhears the
utterance of some other group which lacks some of its evidence.)



Relativist treatments of various expressions have also been motivated
by certain apparent facts about disagreement. Lasersohn (2005)
considers the example of predicates of personal taste. He points out
that we're often inclined to think that, if our tastes differ
sufficiently, my utterance of "That soup is tasty" can be
true even while your utterance of "That soup is not tasty"
is also true. As above, this fact by itself is not especially
surprising, and might seem to cry out for a contextualist treatment of
"tasty". But the puzzling thing is that, despite the fact
that we think that each of us are uttering sentences which express
true propositions, we are clearly disagreeing with each other. (You
might say, after overhearing me, "*No*, that soup is not
tasty".)



The contrast here with indexicals is apparently quite sharp. If I say
"I'm hungry", and you're not hungry,
you'd never reply to my utterance by saying "No, I'm
not hungry"--precisely because it's obvious that we
would not be disagreeing. So again we have a puzzle: a puzzle about
how each of our "soup" sentences could express true
propositions, despite those propositions contradicting each other.
Relativism suggests an answer: these propositions are only true or
false relative to individuals. The one I express is true relative to
me, and its negation is true relative to you; they're
contradictory in the sense that it is impossible for both to be true
relative to the same individual (at the same time).



It's very controversial whether any of these relativist
arguments are convincing. For more discussion, see the discussion of
"new relativism" in the entry on
 relativism.
 For an explication of relativism and its application to various kinds
of discourse, see MacFarlane (2014). For an extended critique of
relativism, see Cappelen & Hawthorne (2009).


#### 2.3.3 What are propositions, anyway?



Most philosophers believe in propositions, and hence think that
semantics should be done according to one of the three broad
categories of propositionalist approaches sketched above: possible
worlds semantics, Russellianism, or Fregeanism. But it is notable that
of these three views, only one--possible worlds
semantics--actually tells us what propositions are. (Even in that
case, of course, one might ask what possible worlds are, and hence
what propositions are sets *of*. See the entry on
 possible worlds.)
 Russellian and Fregean views make claims about what sorts of things
are the constituents of propositions--but don't tell us
what the structured propositions so constituted are.



There are really two questions here. One is the question: what does it
mean to say that *x* is a constituent of a proposition? The
language of constituency suggests parthood; but there's some
reason to think that *x*'s being a constituent of a
proposition isn't a matter of *x*'s being a part of
that proposition. This is perhaps clearest on a Russellian view,
according to which ordinary physical objects can be constituents of
propositions. The problem is that a thing can be a constituent of a
proposition without every part of that thing being a constituent of
that proposition; a proposition with me as a constituent, it seems,
need not also have every single molecule that now composes me as a
constituent. But that fact is inconsistent with the idea that
constituency is parthood and the plausible assumption that parthood is
transitive. For discussion of this and other problems, see Gilmore
(2014), Keller (2013), and Merricks (2015).



Hence the proponent of structured propositions owes some account of
what "structure" and "constituent" talk
amounts to in this domain. And they can hardly take these notions as
primitive, since it would then be very unclear what explanatory value
the claim that propositions are structured could have.



The second, in some ways more fundamental, question, is: What sort of
thing are propositions? To what metaphysical category do they belong?
The simplest and most straightforward answer to this question is:
"They belong to the *sui generis* category of
propositions". (This is the view of Plantinga (1974) and Merricks (2015).)



But recently many philosophers have sought to give different answers
to this question, by trying to explain how propositions could be
members of some other ontological category in which we have
independent reason to believe. Recent work of this sort can be divided
into three main families of views.



According to the first, propositions are a kind of fact. This view
was, on some interpretations, advocated by Russell (1903) and
Wittgenstein (1922). The most prominent current defender of this view
is Jeffrey King. On his version of the view, propositions (at least
the propositions expressed by sentences) are meta-linguistic facts
about sentences. At a first pass, and ignoring some important
subtleties, the proposition expressed by the sentence "Amelia
talks" will be the fact that there is some language *L*,
some expression *x*, some expression *y*, and some syntactic
relation *R* such that *R*(*x*,*y*), *x* has
Amelia as its semantic value, *y* has the property of talking as
its semantic value, and *R* encodes ascription. In some respects,
this view is not so far from--though much more thoroughly
developed than--Wittgenstein's view in the
*Tractatus* that "a proposition is a propositional sign
in its projective relation to the world" (3.12). See for
development and defense of this view King (2007, 2014).



According to the second sort of view, propositions are kind of
property. Versions of this view vary both according to which
properties they take propositions to be, and what they take
propositions to be properties of. This view is most closely associated
with David Lewis (1979) and Chisholm (1981), who took the objects of
propositional attitudes to be properties which the bearer of the
attitude ascribes to him- or herself. Other versions of the view are
defended by van Inwagen (2004) and Gilmore (forthcoming), who take
propositions to be 0-place relations, and Richard (2013) and Speaks
(2014), who take propositions to be monadic properties of certain
sorts.



According to the third sort of view, propositions are entities which
are, or owe their existence to, the mental acts of subjects. While
their views differ in many ways, both Hanks (2007, 2011) and Soames
(2010, 2014) think of propositions as acts of predication. In the
simplest case--a monadic predication--the proposition will
be the act of predicating a property of an object.



Of course, not all views fit into these three categories. An important
view which fits into none of them is defended in Moltmann (2013).



Different theorists differ, not just in their views about what
propositions are, but also in their views about what a theory of
propositions should explain. The representational properties of
propositions are a case in point. Hanks, King, and Soames take one of
the primary tasks of a theory of propositions to be the explanation of
the representational properties of propositions. Others, like McGlone
(2012) and Merricks (2015), hold that a proposition's having
certain representational properties is a primitive matter. Still
others, like Richard and Speaks, deny that propositions have
representational properties in any interesting sense. See for further
discussion of these issues the entry on
 structured propositions.


## 3. Foundational Theories of Meaning



We now turn to our second sort of "theory of meaning":
foundational theories of meaning, which are attempts to specify the
facts in virtue of which expressions of natural languages come to have
the semantic properties that they have.



The question which foundational theories of meaning try to answer is a
common sort of question in philosophy. In the philosophy of
 action (see entry)
 we ask what the facts are in virtue of which a given piece of
behavior is an intentional action; in questions about
 personal identity (see entry)
 we ask what the facts are in virtue of which *x* and *y*
are the same person; in ethics we ask what the facts are in virtue of
which a given action is morally right or wrong. But, even if they are
common enough, it is not obvious what the constraints are on answers
to these sorts of questions, or when we should expect questions of
this sort to have interesting answers.



Accordingly, one sort of approach to foundational theories of meaning
is simply to deny that there is any true foundational theory of
meaning. One might be quite willing to endorse one of the semantic
theories outlined above while also holding that facts about the
meanings of expressions are primitive, in the sense that there is no
systematic story to be told about the facts in virtue of which
expressions have the meanings that they have. (See, for example,
Johnston 1988.)



There is another reason why one might be pessimistic about the
prospects of foundational theories of meaning. While plainly distinct
from semantics, the attempt to provide foundational theories is
clearly in one sense answerable to semantic theorizing, since without
a clear view of the facts about the semantic contents of expressions
we won't have a clear view of the facts for which we are trying to
provide an explanation. One might, then, be skeptical about the
prospects of foundational theories of meaning not because of a general
primitivist view of semantic facts, but just because one holds that
natural language semantics is not yet advanced enough for us to have a
clear grip on the semantic facts which foundational theories of
meaning aim to analyze. (See for discussion Yalcin (2014).)



Many philosophers have, however, attempted to provide foundational
theories of meaning. This section sets aside pessimism about
the prospects for such theories and lays out the main attempts to give
a systematic account of the facts about language users in virtue of
which their words have the semantic properties that they do. It is
useful to separate these theories into two camps.



According to the first sort of view, linguistic expressions inherit
their contents from some other sort of bearer of content. So, for
example, one might say that linguistic expressions inherit their
contents from the contents of certain mental states with which they
are associated. I'll call views of this type *mentalist*
theories. Mentalist theories are discussed in
 SS3.1,
 and non-mentalist theories in
 SS3.2.


### 3.1 Mentalist Theories



All mentalist theories of meaning have in common that they analyze one
sort of representation--linguistic representation--in terms
of another sort of representation--mental representation. For
philosophers who are interested in explaining content, or
representation, in non-representational terms, then, mentalist
theories can only be a first step in the task of giving an ultimate
explanation of the foundations of linguistic representation. The
second, and more fundamental explanation would then come at the level
of a theory of mental content. (For an overview of theories of this
sort, see entry on
 mental representation
 and the essays in Stich and Warfield 1994.) Indeed, the popularity of
mentalist theories of linguistic meaning, along with the conviction
that content should be explicable in non-representational terms, is an
important reason why so much attention has been focused on theories of
mental representation over the last few decades.



Since mentalists aim to explain the nature of meaning in terms of the
mental states of language users, mentalist theories may be divided
according to which mental states they take to be relevant to the
determination of meaning. The most well-worked out views on this topic
are the Gricean view, which explains meaning in terms of the
communicative intentions of language users, and the view that the
meanings of expressions are fixed by conventions which pair sentences
with certain beliefs. We will discuss these in turn, followed by a
brief discussion of a third alternative available to the
mentalist.


#### 3.1.1 The Gricean program



Paul Grice
 developed an analysis of meaning which can be thought of as the
conjunction of two claims: (1) facts about what expressions mean are
to be explained, or analyzed, in terms of facts about what speakers
mean by utterances of them, and (2) facts about what speakers mean by
their utterances can be explained in terms of their intentions. These
two theses comprise the "Gricean program" for reducing
meaning to the contents of the intentions of speakers.



To understand Grice's view of meaning, it is important first to
be clear on the distinction between the meaning, or content, of
*linguistic expressions*--which is what semantic theories
like those discussed in
 SS2
 aim to describe--and what *speakers* mean by utterances
employing those expressions. This distinction can be illustrated by
example. (See entry on
 pragmatics
 for more discussion.) Suppose that in response to a question about
the weather in the city where I live, I say "Well, South Bend is
not exactly Hawaii". The meaning of this sentence is fairly
clear: it expresses the (true) proposition that South Bend, Indiana is
not identical to Hawaii. But what *I* mean by uttering this
sentence is something more than this triviality: I mean by the
utterance that the weather in South Bend is not nearly as good as that
in Hawaii. And this example utterance is in an important respect very
typical: usually the propositions which speakers mean to convey by
their utterances include propositions other than the one expressed by
the sentence used in the context. When we ask "What did you mean
by that?" we are usually not asking for the meaning of the
sentence uttered.



The idea behind stage (1) of Grice's theory of meaning is that
of these two phenomena, speaker-meaning is the more fundamental:
sentences and other expressions mean what they do because of what
speakers mean by their utterances of those sentences. (For more
details about how Grice thought that sentence-meaning could be
explained in terms of speaker-meaning, see the discussion of resultant
procedures in the entry on
 Paul Grice.)
 One powerful way to substantiate the claim that speaker-meaning is
explanatorily prior to expression-meaning would be to show that facts
about speaker-meaning may be given an analysis which makes no use of
facts about what expressions mean; and this is just what stage (2) of
Grice's analysis, to which we now turn, aims to provide.



Grice thought that speaker-meaning could be analyzed in terms of the
communicative intentions of speakers--in particular, their
intentions to cause beliefs in their audience.



The simplest version of this idea would hold that meaning *p* by
an utterance is just a matter of intending that one's audience
come to believe *p*. But this can't be quite right. Suppose
I turn to you and say, "You're standing on my foot".
I intend that you hear the words I am saying; so I intend that you
believe that I have said, "You're standing on my
foot". But I do not mean by my utterance that I have said,
"You're standing on my foot". That *is* my
utterance--what I mean by it is the proposition that you are
standing on my foot, or that you should get off of my foot. I do not
mean by my utterance that I am uttering a certain sentence.



This sort of example indicates that speaker meaning can't just
be a matter of intending to cause a certain belief--it must be
intending to cause a certain belief in a certain way. But what, in
addition to intending to cause the belief, is required for meaning
that *p*? Grice's idea was that one must not only intend to
cause the audience to form a belief, but also intend that they do so
on the basis of their recognition of the speaker's intention.
This condition is not met in the above example: I don't expect
you to believe that I have uttered a certain sentence on the basis of
your recognition of my intention that you do so; after all,
you'd believe this whether or not I wanted you to. This is all
to the good.



This Gricean analysis of speaker-meaning can be formulated as
 follows:[5]


* [G] *a* means
*p* by uttering *x* iff *a* intends in uttering
*x* that
* 1.
his audience come to
believe *p*,
* 2.
 his audience recognize
this intention, and
* 3.
 (1) occur on the basis
of (2).



However, even if [G] can be given a fairly plausible motivation, and
fits many cases rather well, it is also open to some convincing
counterexamples. Three such types of cases are: (i) cases in which the
speaker means *p* by an utterance despite knowing that the
audience already believes *p*, as in cases of reminding or
confession; (ii) cases in which a speaker means *p* by an
utterance, such as the conclusion of an argument, which the speaker
intends an audience to believe on the basis of evidence rather than
recognition of speaker intention; and (iii) cases in which there is no
intended audience at all, as in uses of language in thought. These
cases call into question whether there is any connection between
speaker-meaning and intended effects stable enough to ground an
analysis of the sort that Grice envisaged; it is still a matter of
much controversy whether an explanation of speaker meaning descended
from [G] can succeed.



For developments of the Gricean program, see--in addition to the
classic essays in Grice (1989)--Schiffer (1972), Neale (1992),
and Davis (2002). For an extended criticism, see Schiffer (1987).


#### 3.1.2 Meaning, belief, and convention



An important alternative to the Gricean analysis, which shares the
Gricean's commitment to a mentalist analysis of meaning in terms
of the contents of mental states, is the analysis of meaning in terms
of the *beliefs* rather than the intentions of speakers.



It is intuitively plausible that such an analysis should be possible.
After all, there clearly are regularities which connect utterances and
the beliefs of speakers; roughly, it seems that, for the most part,
speakers seriously utter a sentence which (in the context) means
*p* only if they also believe *p*. One might then, try to
analyze meaning directly in terms of the beliefs of language users, by
saying that what it is for a sentence *S* to express some
proposition *p* is for it to be the case that, typically, members
of the community would not utter *S* unless they believed
*p*. However, we can imagine a community in which there is some
action which everyone would only perform were they to believe some
proposition *p*, but which is such that no member of the
community knows that any other member of the community acts according
to a rule of this sort. It is plausible that in such a community, the
action-type in question would not express the proposition *p*, or
indeed have any meaning at all.



Because of cases like this, it seems that regularities in meaning and
belief are not sufficient to ground an analysis of meaning. For this
reason, many proponents of a mentalist analysis of meaning in terms of
belief have sought instead to analyze meaning in terms of
*conventions* governing such regularities. Roughly, a
regularity is a matter of convention when the regularity obtains
because there is something akin to an agreement among a group of
people to keep the regularity in place. So, applied to our present
example, the idea would be (again roughly) that for a sentence
*S* to express a proposition *p* in some group is for there
to be something like an agreement in that group to maintain some sort
of regularity between utterances of *S* and agents'
believing *p*. This seems to be what is lacking in the example
described in the previous paragraph.



There are different ways to make this rough idea precise (see the
entry on
 convention).
 According to one important view, a sentence *S* expresses the
proposition *p* if and only if the following three conditions are
satisfied: (1) speakers typically utter *S* only if they believe
*p* and typically come to believe *p* upon hearing *S*,
(2) members of the community believe that (1) is true, and (3) the
fact that members of the community believe that (1) is true, and
believe that other members of the community believe that (1) is true,
gives them a good reason to go on acting so as to make (1) true. (This
a simplified version of the theory defended in David Lewis 1975.)



For critical discussion of this sort of analysis of meaning, see Burge
1975, Hawthorne 1990, Laurence 1996, and Schiffer 2006.


#### 3.1.3 Mental representation-based theories



The two sorts of mentalist theories sketched above both try to explain
meaning in terms of the relationship between linguistic expressions
and propositional attitudes of users of the relevant language. But
this is not the only sort of theory available to a theorist who wants
to analyze meaning in terms of broadly mental representation. A common
view in the philosophy of mind and cognitive science is that the
propositional attitudes of subjects are underwritten by an internal
language of thought, comprised of mental representations. (See entry
on
 the computational theory of mind.)
 One might try to explain linguistic meaning directly in terms of the
contents of mental representations, perhaps by thinking of language
processing as pairing linguistic expressions with mental
representations; one could then think of the meaning of the relevant
expression for that individual as being inherited from the content of
the mental representation with which it is paired.



While this view has, historically, not enjoyed as much attention as
the mentalist theories discussed in the preceding two subsections, it
is a natural view for anyone who endorses the widely held thesis that
semantic competence is to be explained by some sort of internal
representation of the semantic facts. If we need to posit such
internal representations anyway, it is natural to think that the
meaning of an expression for an individual can be explained in terms
of that individual's representation of its meaning. For discussion of
this sort of theory, see Laurence (1996).



Just as proponents of Gricean and convention-based theories typically
view their theories as only the first stage in an analysis of
meaning--because they analyze meaning in terms of another sort of
mental representation--so proponents of mental
representation-based theories will typically seek to provide an
independent analysis of contents of mental representations. For an
overview of attempts to provide the latter sort of theory, see the
entry on
 mental representation
 and the essays in Stich and Warfield (1994).


### 3.2 Non-Mentalist Theories



As noted above, not all foundational theories of meaning attempt to
explain meaning in terms of mental content. One might be inclined to
pursue a non-mentalist foundational theory of meaning for a number of
reasons; for example, one might be skeptical about the mentalist
theories on offer; one might think that mental representation should
be analyzed in terms of linguistic representation, rather than the
other way around; or one might think that representation should be
analyzable in non-representational terms, and doubt whether there is
any true explanation of mental representation suitable to accompany a
mentalist reduction of meaning to mental representation.



To give a non-mentalist foundational theory of meaning is to say which
*aspects* of the use of an expression determine
meaning--and do so without taking that expression to simply
inherit its content from some more fundamental bearer of content. In
what follows I'll briefly discuss some of the aspects of the use
of expressions which proponents of non-mentalist theories have taken
to explain their meanings.


#### 3.2.1 Causal origin



In *Naming and Necessity*, Kripke suggested that the reference
of a name could be explained in terms of the history of use of that
name, rather than by descriptions associated with that name by its
users. In the standard case, Kripke thought, the right explanation of
the reference of a name could be divided into an explanation of the
name's *introduction* as name for this or that--an
event of "baptism"--and its successful
*transmission* from one speaker to another.



One approach to the theory of meaning is to extend Kripke's
remarks in two ways: first, by suggesting that they might serve as an
account of meaning, as well as
 reference;[6]
 and second, by extending them to parts of speech other than names.
(See, for discussion, Devitt 1981.) In this way, we might aim to
explain the meanings of expressions in terms of their causal
origin.



While causal theories don't take expressions to simply inherit
their contents from mental states, it is plausible that they should
still give mental states an important role to play in explaining
meaning. For example, it is plausible that introducing a term involves
*intending* that it stand for some object or property, and that
transmission of a term from one speaker to another involves the latter
*intending* to use it in the same way as the former.



There are two standard problems for causal theories of this sort
(whether they are elaborated in a mentalist or a non-mentalist way).
The first is the problem of extending the theory from the case of
names to to other sorts of vocabulary for which the theory seems less
natural. Examples which have seemed to many to be problematic are
empty names and non-referring theoretical terms, logical vocabulary,
and predicates which, because their content does not seem closely
related to the properties represented in perceptual experience, are
not intuitively linked to any initial act of "baptism".
The second problem, which is sometimes called the "*qua*
problem", is the problem of explaining which of the many causes
of a term's introduction should determine its content. Suppose
that the term "water" was introduced in the presence of a
body of H2O. What made it a term for this substance, rather
than for liquid in general, or colorless liquid, or colorless liquid
in the region of the term's introduction? The proponent of a causal
theory owes some answer to this question; see for discussion Devitt
and Sterelny (1987).



For a classic discussion of the prospects of causal theories, see
Evans (1973). For a
recent theory which makes causal origin part but not all of the story,
see Dickie (2015).


#### 3.2.2 Truth-maximization and the principle of charity



Causal theories aim to explain meaning in terms of the relations
between expressions and the objects and properties they represent. A
very different sort of foundational theory of meaning which maintains
this emphasis on the relations between expressions and the world gives
a central role to a *principle of charity* which holds that
(modulo some qualifications) the right assignment of meanings to the
expression of a subject's language is that assignment of
meanings which maximizes the truth of the subject's
utterances.



An influential proponent of this sort of view was Donald Davidson, who
stated the motivation for the view as follows:



> 
> 
> A central source of trouble is the way beliefs and meanings conspire
> to account for utterances. A speaker who holds a sentence to be true
> on an occasion does so in part because of what he means, or would
> mean, by an utterance of that sentence, and in part because of what he
> believes. If all we have to go on is the fact of honest utterance, we
> cannot infer the belief without knowing the meaning, and have no
> chance of inferring the meaning without the belief. (Davidson 1974a:
> 314; see also Davidson 1973)
> 
> 
> 



Davidson's idea was that attempts to state the facts in virtue
of which expressions have a certain meaning for a subject face a kind
of dilemma: if we had an independent account of what it is for an
agent to have a belief with a certain content, we could ascend from
there to an account of what it is for a sentence to have a meaning; if
we had an independent account of what it is for a sentence to have a
meaning, we could ascend from there to an account of what it is for an
agent to have a belief with a certain content; but in fact neither
sort of independent account is available, because many assignments of
beliefs and meanings are consistent with the subject's
linguistic behavior. Davidson's solution to this dilemma is that
we must define belief and meaning together, in terms of an independent
third fact: the fact that the beliefs of an agent, and the meanings of
her words, are whatever they must be in order to maximize the truth of
her beliefs and utterances.



By tying meaning and belief to truth, this sort of foundational theory
of meaning implies that it is impossible for anyone who speaks a
meaningful language to be radically mistaken about the nature of the
world; and this implies that certain levels of radical disagreement
between a pair of speakers or communities will also be impossible
(since the beliefs of each community must be, by and large, true).
This is a consequence of the view which Davidson embraced (see
Davidson 1974b); but one might also reasonably think that radical
disagreement, as well as radical error, are possible, and hence that
any theory, like Davidson's, which implies that they are
impossible must be mistaken.



A different sort of worry about a theory of this sort is that the
requirement that we maximize the truth of the utterances of subjects
hardly seems sufficient to determine the meanings of the expressions
of their language. It seems plausible, offhand, that there will be
many different interpretations of a subject's language which
will be tied on the measure of truth-maximization; one way to see the
force of this sort of worry is to recall the point, familiar from our
discussion of possible worlds semantics in
 SS2.1.5
 above, that a pair of sentences can be true in exactly the same
circumstances and yet differ in meaning. One worry is thus that a
theory of Davidson's sort will entail an implausible
indeterminacy of meaning. For Davidson's fullest attempt to
answer this sort of worry, see Chapter 3 of Davidson (2005).


#### 3.2.3 Reference magnetism



A different sort of theory emerges from a further objection to the
sort of theory discussed in the previous section. This objection is
based on Hilary Putnam's (1980, 1981) model-theoretic argument.
This argument aimed to show that there are very many different
assignments of reference to subsentential expressions of our language
which make all of our utterances true. (For details on how the
argument works, see the entry on
 Skolem's paradox,
 especially SS3.4.) Putnam's argument therefore leaves us
with a choice between two options: either we must accept that there
are no facts of the matter about what any of our expressions refer to,
or we must deny that is determined solely by a principle of
truth-maximization.



Most philosophers take the second option. Doing so, however,
doesn't mean that something like the principle of charity
can't still be part of our foundational theory of meaning.



David Lewis (1983, 1984) gave a version of this kind of response,
which he credits to Merrill (1980), and which has since been quite
influential. His idea was that the assignment of contents to
expressions of our language is fixed, not just by the constraint that
the right interpretation will maximize the truth of our utterances,
but by picking the interpretation which does best at jointly
satisfying the constraints of truth-maximization and the constraint
that the referents of our terms should, as much as possible, be
"the ones that respect the objective joints in nature"
(1984: 227).



Such entities are often said to be more "eligible" to be
the referents of expressions than others. An approach to the
foundations of meaning based on the twin principles of charity +
eligibility has some claim to being the most widely held view today.
See Sider (2011) for an influential extension of the Lewisian
strategy.



Lewis' solution to Putnam's problem comes with a
non-trivial metaphysical price tag: recognition of an objective graded
distinction between more and less natural properties. Some have found
the price too much to pay, and have sought other approaches to the
foundational theory of meaning. But even if we recognize in our
metaphysics a distinction between properties which are
"joint-carving" and those which are not, we might still
doubt whether this distinction can remedy the sorts of indeterminacy
problems which plague foundational theories based solely on the
principle of charity. For doubts along these lines, see Hawthorne
(2007).


#### 3.2.4 Regularities in use



A different way to develop a non-mentalist foundational theory of
meaning focuses less on relations between subsentential expressions or
sentences and bits of non-linguistic reality and more on the
regularities which govern our use of language. Views of this sort have
been defended by a number of authors; this section focuses on the
version of the view developed in Horwich (1998, 2005).



Horwich's core idea is that our acceptance of sentences is
governed by certain laws, and, in the case of non-ambiguous
expressions, there is a single "acceptance regularity"
which explains all of our uses of the expression. The type of
acceptance regularity which is relevant will vary depending on the
sort of expression whose meaning is being explained. For example, our
use of a perceptual term like "red" might be best
explained by the following acceptance regularity:



> 
> 
> The disposition to accept "that is red" in response to the
> sort of visual experience normally provoked by a red surface.
> 
> 
> 



whereas, in the case of a logical term like "and", the
acceptance regularity will involve dispositions to accept inferences
involving pairs of sentences rather than dispositions to respond to
particular sorts of experiences:



> 
> 
> The disposition to accept the two-way argument schema "*p*,
> *q* // *p* and *q*".
> 
> 
> 



As these examples illustrate, it is plausible that a strength of a
view like Horwich's is its ability to handle expressions of
different categories.



Like its competitors, Horwich's theory is also open to some
objections. One might worry that his use of the sentential attitude of
acceptance entails a lapse into mentalism, if acceptance either just
is, or is analyzed in terms of, beliefs. There is also a
worry--which affects other "use" or "conceptual
role" or "functional role" theories of
meaning--that Horwich's account implies the existence of
differences in meaning which do not exist; it seems, for example, that
two people's use of some term might be explained by distinct
basic acceptance regularities without their meaning different things
by that term. Schiffer (2000) discusses the example of
"dog", and the differences between the basic acceptance
regularities which govern the use of the term for the blind, the
biologically unsophisticated, and people acquainted only with certain
sorts of
 dogs.[7]


#### 3.2.5 Social norms



This last concern about Horwich's theory stems from the fact
that the theory is, at its core, an individualist theory: it explains
the meaning of an expression for an individual in terms of properties
of that individual's use of the term. A quite different sort of
use theory of meaning turns from the laws which explain an
individual's use of a word to the norms which, in a society,
govern the use of the relevant terms. Like the other views discussed
here, the view that meaning is a product of social norms of this sort
has a long history; it is particularly associated with the work of the
later Wittgenstein and his philosophical descendants. (See especially
Wittgenstein 1953.)



An important defender of this sort of view is Robert Brandom. On
Brandom's view, a sentence's meaning is due to the
conditions, in a given society, under which it is correct or
appropriate to perform various speech acts involving the sentence. To
develop a theory of this sort, one must do two things. First, one must
show how the meanings of expressions can be explained in terms of
these normative statuses--in Brandom's (slightly
nonstandard) terms, one must show how semantics can be explained in
terms of pragmatics. Second, one must explain how these normative
statuses can be instituted by social practices.



For details, see Brandom (1994), in which the view is developed at
great length; for a critical discussion of Brandom's attempt to
carry out the second task above, see Rosen (1997). For discussion of
the role (or lack thereof) of normativity in a foundational theory of
meaning, see Hattiangadi (2007), Gluer and Wilkforss (2009), and the
entry on
 meaning normativity.