Two Concepts of Rationality

RATIONALITY IS ESSENTIALLY connected with norms. In Western philosophy, while there has been much disagreement over what the norms of rationality are, there seems to have been substantial agreement that these norms are narrowly prescriptive; in fact there is a pronounced tendency to see rationality as leaving the agent no scope for choice in matters of thought, belief, inference and behaviour. On this pervasive view, rationality dictates: either one accepts, believes, infers or does what rationality says one should, or one is irrational. I will argue that this authoritarian concept of rationality is absurd. I contrast it with a libertarian concept of rationality, derived from the critical rationalism of Karl Popper. I argue that, while this approach avoids the absurdities of the authoritarian one, it requires some further development. To keep the discussion within a reasonable compass, after outlining the two concepts with regard to both theoretical and practical rationality, I discuss them critically with respect to theoretical rationality only; the comparison with respect to practical rationality is left for another occasion. However, as the distinction between theoretical and practical rationality is somewhat artificial, parts of the following discussion will inevitably cross over into some matters of practical rationality.