Propositional Attitude Ascription

Abstract

Propositional attitude verbs – examples are ‘believes,’ ‘says,’ ‘wonders,’ and ‘wants’ – are certain verbs which take clausal complements (e.g., ‘that it’s sunny,’ ‘whether it’s snowing’) as arguments. Propositional attitude ascriptions – sentences such as ‘Margaret believes that Tom is in Australia’ – are ones whose main verb is a verb of propositional attitude. Common to such sentences is that they ascribe psychological states (such as belief and desire) or speech acts (assertions, suggestings, and so forth). Propositional attitude ascriptions (PAs) are paradigms of non-extensionality: replacing one sentence, predicate, or term following a propositional attitude verb with another with the same extension may change the ascription’s truth value. Someone may, for example, wish that the British Prime Minister would come without wishing that Mrs. Blair’s husband come. Truth value may apparently change even on replacement of an expression by one with the same (possible worlds) intension. One might, it seems, guess that Twain wrote a book without guessing that Clemens did; ‘Twain’ and ‘Clemens,’ conventional wisdom tells us, have the same intension, being rigid designators of one individual. Whence this non-extensionality? The standard answer flows from the syntax of PAs. To say that a PAs complement clause is an argument is to make a syntactic claim, mandated by syntactic facts. Verbs of propositional attitude (VPAs) require complementation: ‘I believe’ and ‘I guess’ are acceptable only if elliptical for