Abstract

The age of Enlightenment has, upon refl ection, turned out to be an age of exclusion. Part of the explanation for this is that Descartes’ inward turn leaves reason unable to rely on anything other than its own resources. Rather than give in to cultural relativism, philosophers of the time deny the epistemic and moral agency of those who are different from themselves. Even as philosophy rejects its Cartesian heritage, the same dilemma faces us: fi nd some uniformity and regularity within cognition or accept the legitimacy of all sorts of cognition. This dilemma, however, can be dissolved by appealing to a practice closely related to being rational but that is decidedly non-modern in approach, namely, reasonableness. The concept of reasonableness accounts for humans’ diverse capacity to reason while providing some normative expectations across various practices.