Camilo Martinez

According to anti-structuralists about rationality, such as Errol Lord and Benjamin Kiesewetter, incoherence is irrational because it guarantees a failure to respond to one's possessed reasons. For example, since having sufficient evidence for believing p entails not having sufficient evidence for believing not-p, it must be unreasonable to hold both beliefs. I argue that one of the most compelling explanations of how incoherence is psychologically possible, the fragmentation hypothesis, undermines this account of why it is irrational. When one's beliefs are fragmented, there is no guarantee that being reasonable is sufficient for being coherent.

Why do we have social norms—of fairness, cooperation, trust, property, or gender? Modern-day Humeans, as I call them, believe these norms are best accounted for in cultural evolutionary terms, as adaptive solutions to recurrent problems of social interaction. In this paper, I discuss a challenge to this “Humean Program.” Social norms involve widespread behaviors, but also distinctive psychological attitudes and dispositions. According to the challenge, Humean accounts of norms leave their psychological side unexplained. They explain, say, why we share equally, but not why we disapprove of those who don’t. I defend the Humean Program against this challenge. In particular, I suggest an idea for how to extend the Program to account for the psychological side of norms. Socially adaptive behaviors aren’t just likely to emerge in a group; They are also likely to be widely taught within it. The transmission of these behaviors through instruction explains why they are associated with distinctive normative attitudes and dispositions. These attitudes play a pedagogical role in helping transmit these behaviors to children and newcomers.

According to many philosophers, rationality is, at least in part, a matter of one’s attitudes cohering with one another. Theorists who endorse this idea have devoted much attention to formulating various coherence requirements. Surprisingly, they have said very little about what it takes for a set of attitudes to be coherent in general. We articulate and defend a general account on which a set of attitudes is coherent just in case and because it is logically possible for the attitudes to be jointly satisfied in the sense of jointly fitting the world. In addition, we show how the account can help adjudicate debates about how to formulate various rational requirements.