Objections to Desirism: Ought not to φ implies having a reason not to φ.

This post considers the objection that desirism is in conflict with the claim that if one ought not to do something then one must have a reason not to do it. I look specifically at this claim as it appears in Richard Joyce's defense of error theory. I argue that it is not true by showing that it is incompatible both with how excuses function in the common use of terms and the requirement that an…