The Classical Model of Rationality and its Weaknesses

Abstract

In our intellectual culture, we have a quite specific tradition of discussing rationality and practical reason, rationality in action. This tradition goes back to Aristotle’s claim that deliberation is always about means, never about ends, it continues in Hume’s famous claim that, “Reason is and ought only to be the slave of the passions”, and in Kant’s claim that, “He who wills the end wills the means”. The tradition receives its most sophisticated formulation in contemporary mathematical decision-theory. The tradition is by no means unified, and I would not wish to suggest that Aristotle, Hume, and Kant share the same conception of rationality. On the contrary, there are striking differences between them. But there is a common thread, and I believe that of the classical philosophers, Hume gives the clearest statement of what I will be referring to as “the Classical Model”. I have for a long time had doubts about this tradition and I am going to spend most of this essay exposing some of its main features and making a preliminary statement of some of my doubts.