Kant’s most canonical argument against suicide, the universal law argument, is widely dismissed. This paper attempts to save it, showing that a suicide maxim, universalized, undermines all bases for practical law, resisting both the non-negotiable value of free rational willing and the ordinary array of sensuous commitments that inform prudential incentives. Suicide therefore undermines moral law-governed community as a whole, threatening ‘savage disorder’. In pursuing this argument, I propose a non-teleological and non-theoretical nature – a ‘practical nature’ or moral law governed whole – the realization of which morality demands.