03/06 - Pedro Carrasqueira

On the foundations of a theory of deliberative reason: A logical survey of the general principles of the theory of rational choices and coherent preferences

Last century witnessed a great development of the mathematical foundations of social sciences, due to the rapid growth of research in decision theory, game theory and social choice theory and to the astounding results obtained in those fields. Such studies seem to me to point towards a more general theory of rationality in practical contexts, and, in particular, to a mathematical theory of deliberative reason. Such a possibility, however, presupposes a (to the best of my knowledge) not yet systematically undertaken philosophical inquiry of the principles underlying those theories, --- one that would explore their pertinence to settings broader than those proper to the social sciences.

My exposition shall be divided in three parts.

In the first part I shall present the main concepts common to all those theories --- to wit, the notions of choicepreferencewelfare, norm and strategy --- and discuss in very broad strokes how they relate, with special attention to the relation between the more fundamental concepts of choice and preference. (I say they are more fundamental because they seem to me to be the ones that characterize, minimally, a deliberative setting.)

In the second part I shall briefly discuss what contributions (beyond the already well-known use of games in model theory) I believe such an enlargement of the field of application of those concepts would have to offer to logic in general, and to logic in practical contexts in particular.

In the third part I shall present a few questions about how already well-established logic, and modal logic in particular, could contribute to the understanding of those fundamental concepts of deliberative reason. I shall also present, if time allows it, some still very sketchy proposals of mine towards such a contribution.