One reasons not just in beliefs, but also in intentions, preferences, and other attitudes. For instance, one forms preferences from preferences, or intentions from beliefs and preferences. Formal logic has proved useful for modelling reasoning in beliefs -- the formation of beliefs from beliefs. Can logic also model reasoning in multiple attitudes? We identify principled obstacles. Logic can model reasoning about attitudes. But this models the discovery of attitudes of (usually) others, not the formation of one's own attitudes. Beliefs are special in that reasoning in beliefs can follow logical entailment between belief contents. This makes beliefs the privileged target of logic, when applying logic to psychology.