Abstract

Are inferences, theoretical and practical, subject to requirements of rationality? If so, are these of the form 'if … ought …' or 'ought … if …'? If the latter, how are we to understand the 'if'? It seems that, in all cases, we get unintuitive implications if 'ought' connotes having reason. It is difficult to formulate such requirements, and obscure what they explain. There might also be a requirement forbidding self-contradiction. It is a good question whether self-contradiction constitutes, or evidences, irrationality; but talk of a rational requirement causes trouble.