Abstract

Philosophers have long distinguished between practical and theoretical rationality. The first section of this chapter begins by discussing the ways in which this distinction was drawn by Aristotle and Kant; then it sketches what seems to be the general consensus today about how, at least roughly, the distinction should be drawn. The rest of this chapter explores what practical and theoretical rationality have in common: in the second section, several parallels between practical and theoretical rationality are outlined, and it is argued that these parallels make it plausible that a unifying account of rationality can be given. Finally, in the third section, a number of such unifying accounts of practical and theoretical rationality are surveyed. These include accounts that are inspired in various ways by Hume and by the results of formal decision theory, as well as views that appeal to reasons and to the distinctive value of correct or appropriate attitudes.