Abstract

The paper constitutes a detailed critical commentary on Stephen Darwall’s Impartial Reason (Ithaca: Cornell University Press, 1983). Its central thesis is that Darwall’s attempt to integrate a naturalist theory of substantive reasons for acting with a neo-rationalist derivation of moral requirements from the very concept of practical rationality is faced with insurmountable theoretic problems. The author argues that anyone who would accept a plausible internalist account of reasons, that justificatory reasons for an agent to act are facts which must be capable of motivating that agent under certain conditions, cannot establish on an a priori or rationalist basis claims for the intersubjective validity of reasons or substantive normative requirements of any kind, but rather must acknowledge that such claims are both irreducibly empirical and epistemically risky.