Synonymy and Equivocation in Ockham's Mental Language

Abstract

In I957 Peter Geach argued that Ockham's theory of mental language was too facile, that it made the grammar of mental language look too suspiciously like that of Latin: "He merely transfers features of Latin grammar to Mental, and then regards this as explaining why such features occur in Latin -- they are needed there if what we say inwardly in Mental is to be outwardly got across to others in Latin. But clearly nothing is explained at all.'' In 1970 John Trentman responded to this charge in a short article that has since become very influential. In that article Trentman makes three claims among others: (1) Ockham thought of mental language as a kind of stripped-down, "ideal" language, containing just those grammatical features that affect the truth conditions of mental sentences. (2) There can be no synonymy in mental language. (3) There can be no equivocation in mental language. This paper examines these three claims in turn. Each of them is "correct" in the sense that Ockham either explicitly holds it or else seems committed to holding it on the basis of other features of his thought. Nevertheless, I maintain, each of these claims also leads to difficulties for Ockham, either (with respect to the first claim) because there are certain empirical, linguistic reasons of a sort Ockham would accept for rejecting the claim as it stands, or else (with respect to the second and third claims) because it conflicts with things Ockham says elsewhere.