In this paper, I investigate the non-rational, affective dimension of religious experience that Rudolf Otto attempted to address with his notion of the numinous. I argue that this notion is best understood in terms of an atmospheric quality impacting on the subject's feeling body. Therefore, I draw on discussions in phenomenology and pragmatism, despite the fact that Otto's own epistemological framework is rooted in a different tradition. Drawing on those discussions helps defend some of Otto's claims about the relation between the non-rational, affective dimension and reason against the prevalent accusation of unscientific mysticism. I then illustrate the yet unexhausted potential of these very claims by arguing that the numinous in Otto's sense plays an irreducible role in the ethical reflections of such distinct authors as Kant and Levinas.
