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. (shrink)

This thesis offers a naturalist revision of Alain Badiou’s philosophy. This goal is pursued through an encounter of Badiou’s mathematical ontology and theory of truth with contemporary trends in philosophy of mathematics and philosophy of science. I take issue with Badiou’s inability to elucidate the link between the empirical and the ontological, and his residual reliance on a Heideggerian project of fundamental ontology, which undermines his own immanentist principles. I will argue for both a bottom-up naturalisation of Badiou’s philosophical approach (...) to mathematics and a top-down naturalisation. Articulating my particular understanding of what realism and naturalism should commit us to, I propose a creative fusion of Badiou’s attention to metamathematical results with a structural-informational metaphysics, proposing a ‘matherialism’ uniting the more daring speculative insights of the former with the naturalist and empiricist commitments motivating the latter. (shrink)