Comment on David Chalmers' "probability and propositions"
Propositions are the referents of the ‘that’-clauses that appear in the direct object positions of typical ascriptions of assertion, belief, and other binary cognitive relations. In that sense, propositions are the objects of those cognitive relations. Propositions are also the semantic contents (meanings, in one sense ) of declarative sentences, with respect to contexts. They are what sentences semantically express, with respect to contexts. Propositions also bear truth-values. The truth-value of a sentence, in a context, is the truth-value of the proposition that it semantically expresses, in that context. This much is common ground among many (but not all) philosophers. I accept other claims about propositions that are more controversial. Propositions (I hold) are Russellian: they are structured entities whose constituents include individuals, properties, and relations. The contribution of a proper name to the proposition that a sentence semantically expresses (in a context) is the referent of that name. Thus, the semantic content of ‘Bill Clinton’ is Bill Clinton himself, and the semantic content of ‘Bill Clinton smokes’ is a proposition whose constituents are Bill Clinton and the property of smoking (ignoring tense, as I shall do from here on). Such 1 singular propositions are among the objects of belief, assertion, and other cognitive relations. This combination of a Millian view about proper names with a Russellian theory of propositions might appropriately be called ‘Millian Russellianism’, or ‘MR’ for short. David Chalmers, in his stimulating paper “Probability and Propositions,” defines a closely related view, Referentialism, as follows (see also the penultimate paragraph of his introduction). Referentialist views say that insofar as beliefs are about individuals (such as Nietzche), the objects of these belief are determined by those individuals. On one such view, the objects of belief are Russellian propositions composed from the individuals and properties that one’s belief is about..