Scott Aikin

This article poses two regresses for justification of moral knowledge and discusses three models for moral epistemic infinitism that arise. There are moral infinitisms dependent on empirical infinitism, what are called “piggyback” moral infinitisms. There are substantive empiricist moral infinitisms, requiring infinite chains of descriptive facts to justify normative rules. These empiricist infinitisms are developed either as infinitist egoisms or as infinitist sentimentalisms. And, finally, there are substantive rationalist moral infinitisms, requiring infinite chains of normative reasons to justify moral rules. Rationalist moral infinitism is posed as a mixed view integrating moral intuitions with the demand for justifying reasons.