Jerry Fodor On Mental States - The Hypothesis of Fusion

The Hypothesis of Fusion

Given that Fodor accepts the relational nature of intentional attitudes, his first step is to try to clear the field of those who deny such a nature. Some authors, in fact, sustain the position (which Fodor calls the hypothesis of fusion) for which intentional attitudes are really "monadic" mental states. According to this view, "Simon believes that the Morning Star is Venus" expresses a mental state characterized by an individual "Simon" and a unary predicate "believes-that-the-Morning-Star-is-Venus" in which the verb of believing is semantically fused with the object of belief. Fodor presents several arguments, of which just two will be cited here, against this thesis:

1) There are a very large number of sentences of the form a believes complement. If all these sentences are atomic, how could human beings possibly learn English? (Fodor attributes this to Davidson, 1965).

2) Different propositional attitudes frequently converge on the same content: e.g., one can both fear and believe that it will rain on Tuesday. But, according to the fusion thesis, except for the reference to John, "John fears that it will rain on Tuesday" has nothing in common with "John believes that it will rain on Tuesday." In particular, the fact that the form of the words "it will rain on Tuesday" occurs in both sentences is just an accident.