Individual beliefs, intentions, doubts and desires owe their identities in part to their position in a large network of further attitudes: the character of a given belief depends on endless other beliefs; beliefs have the role they do because of their relations to desires and intentions and perceptions. These relations between the attitudes are essentially logical: the content of an attitude cannot be divorced from what it entails and what is entailed by it. This places a normative constraint on the correct attribution of attitudes: since an attitude is in part identified by its logical relations, the pattern of attitudes in an individual must exhibit a large degree of coherence. This does not mean that people may not be irrational. But the possibility of irrationality depends on a background of rationality; to imagine a totally irrational animal is to imagine an animal without thoughts.