Abstract: Applies Davidson's Unified Theory of thought, meaning, and action to three families of problems involving various aspects of rationality, some degree of which Davidson's theory of radical interpretation attributes to any creature, which can be said to have a mind. These problems are the nature and our understanding of value judgements, the adequacy conditions for attributing mental states to a being, and the problem of irrationality.The first four chapters apply Davidson's thesis that our interpretations of another person's mental states are a source of objectivity to value judgements: such judgements, Davidson argues in this section, are as objective as any judgement about the mind can be. Chs 5 to 10 develop Davidson's Unified Theory for interpreting thought, meaning, and action, the primary concern of this section being the specification of the minimal conditions for attributing mental states to an object or creature. Chs 11 to 14 deal primarily with the problems raised by those cognitive states and actions that seem to violate, in a fundamental way, the constraints of rationality. Since Davidson regards the constraints of rationality to be amongst the necessary conditions for both mind and interpretation, irrational thoughts, and actions pose a particular problem for his Unified Theory. The final four chapters attempt to remove the apparent contradiction.

Keywords: action, constraints of rationality, Donald Davidson, irrationality, meaning, mental states, mind, objectivity, Problems of Rationality, radical interpretation, thought, value judgements