Abstract rationality: the ‘logical’ structure of attitudes

We present an abstract model of rationality that focuses on structural properties of attitudes. Rationality requires coherence between your attitudes, such as your beliefs, values and intentions. We define three ‘logical’ conditions on attitudes: consistency, completeness and closedness. They parallel the familiar logical conditions on beliefs, but contrast with standard rationality conditions such as preference transitivity. We establish a formal correspondence between our logical conditions and standard rationality conditions. Addressing John Broome’s programme ‘rationality through reasoning’, we formally characterize how you can (not) become more logical by reasoning. Our analysis connects rationality with logic, and enables logical talk about multi-attitude psychology.