Consequences of comparability

Abstract

We defend three claims about preference, credence, and choice. First, all agents (not just rational ones) have complete preferences. Second, all agents (again, not just rational ones) have real-valued credences in every proposition in which they are confident to any degree. Third, there is almost always some unique thing we ought to do, want, or believe. These claims may seem absurd. But as we will show, they follow from certain hard-to-resist premises by a principle of the logic of comparatives that we call Comparability. This principle requires, to a first approximation, that if two things are not equally F, then one must be more F than the other. Although many philosophers have rejected Comparability, it is widely assumed in the semantics literature on gradable adjectives and other comparative expressions. In a companion paper (Dorr, Nebel, and Zuehl 2021) we defend its validity. In the present paper, we take Comparability for granted and use it to argue for further controversial conclusions. Of course, those who reject these conclusions may prefer to read the present paper as providing a further battery ofmodus tollens arguments to back up the putative counterexamples that have already convinced so many philosophers to reject Comparability. But we argue, in each case, that the consequences of Comparability are less implausible than they might initially seem. We provide the necessary background in section 1. The rest of the paper draws out our central claims for preference, credence, and choice.