Keelefilosoofia raamat
renate that was not cordate" and "Geoff believes that his pet turtle is a renate"
would have to accommodate (indeed predict) the noninterchangeability of
"cordate" for "renate" in those sentences.
Rejoinder to the second reply
Such sentences--in which coextensive terms cannot be substituted without
possibly changing the truth-value of the sentences themselves--are puzzling
in their own right. (They are called intensional sentences; this is a generaliza-
tion of the phenomenon that in chapter 2 was called "referential opacity.")
One would expect the substitution to make no difference; after all, even if
we are using a different word, we are continuing to talk about exactly the
same thing or class of things. We have already encountered a special case of
this problem in chapters 2 and 3, the Problem of Substitutivity for definite
descriptions and for proper names. Any theory of meaning must offer some
explanation of substitutivity failures
annaabi.ee 
