These are excerpts and elaborations from my book "The Nature of Consciousness"
Truth-conditional Semantics The US philosopher Donald Davidson was the main proponent of
"truth-conditional semantics", which reduces a theory of meaning to a
theory of truth. Tarski simply replaced the universal
and intuitive notion of "truth" with an infinite series of rules
which define truth in a language relative to truth in another language. Davidson would rather assume that the
concept of "truth" need not be defined, that it is known to
everybody. Then he can use the correspondence theory of truth to define
meaning: the meaning of a sentence is defined as what it would be if the
sentence were true. The task for a
theory of meaning then becomes to generate all meta-sentences (or
"T-sentences") for all sentences in the language through a recursive
procedure. This account of meaning
relies exclusively on truth conditions.
A sentence is meaningful in virtue of being true under certain
conditions and not others. To know the
meaning of a sentence is to know the conditions under which the sentence would
be true. A theory of a language must
be able to assign a meaning to every possible sentence of the language. Just
like Chomsky had to include a recursive procedure in order to explain the
speaker's unlimited ability to “recognize” sentences of the language, so
Davidson has to include a recursive procedure in order to explain the speaker's
unlimited ability to “understand” sentences of the language. Natural languages exhibit an
additional difficulty over formal languages: natural languages contain
“deictic” elements (demonstratives, personal pronouns, tenses) which cause the
truth value to fluctuate in time and depend on the speaker. Davidson therefore
proposed to employ a pair of arguments for his truth predicate, one specifying
the speaker and one specifying the point in time. In other words, Davidson
assigns meanings to sentences of a natural language by associating the
sentences with truth-theoretically interpreted formulas of a logical system
(their "logical form"). The US philosopher William
Lycan basically refined Davidson's
meta-theory. Lycan’s theory of linguistic
meaning rests on truth conditions too. All other aspects of semantics
(verification conditions, use in language games, illocutionary force, etc.) are
derived from that notion. A sentence is meaningful by virtue of being true
under certain conditions and not others. However, instead of assigning only a
pair of arguments to the truth predicate, Lycan defines truth as a pentadic
relationship with the logical form, the context (truth is relative to a context
of time and speaker, as specified by some assignment functions), the degree
(languages are inherently vague, and sentences normally contain fuzzy terms and
hedges) and the idiolect (the truth of a sentence is relative to the language
of which it is a grammatical string). Back to the beginning of the chapter "Meaning: Journey to the Center of the Mind" | Back to the index of all chapters |