Intentionality and the Use of Language

Abstract

It is possible to make a reasonably clear distinction between intensionality with an s and intentionality with a t. Without putting too fine a point on it one can say that intensionality-with-an-s is a property of a certain class of sentences. A sentence is intensional if literal utterances of it have at least one interpretation where they fail to satisfy one or more of the standard tests for extensionality. The two tests most relevant to the present discussion are these: if existential generalization over the occurrence of referring expressions is not a valid form of inference or if the sentence fails to allow the substitution salva veritate of expressions which normally have the same reference, then it is intensional-with-an-s. Thus for example, the sentence “John is looking for the lost city of Atlantis” has at least one literal use to make a statement which does not entail that there is a lost city such that John is looking for it. And the sentence “The sheriff believes that Mr. Howard is an honest man” has a literal use to make a statement which together with the true statement that Mr. Howard is identical with Jesse James does not entail that the sheriff believes that Jesse James is an honest man. Because intensional sentences normally derive their intensionality from the occurrence of certain expressions it is possible to speak not only of intensional sentences, but also of intensional verbs, intensional contexts, etc. It is also possible to speak of intensional statements and intensional propositions. No doubt these two tests need some refinement to enable them to cope with sentences other than those used to make statements but the basic idea of intensionality-with-an-s seems reasonably straightforward.