Contemporary discussions of 'corruption' have often been criticised for their narrow focus. Definitions of corruption usually begin with the assumption that it consists in a misuse of public office for private, typically pecuniary gain. Such definitions, it has been argued, exclude earlier and much broader notions of corruption within Western political thought that construe corruption as a loss of virtue. Such understandings of corruption often imbibe assumptions expressed within Aristotelian physics in which corruption denoted the decay or degeneration of physical bodies. The 'moral physics' of corruption thus denoted a degeneration or perversion consisting in a personal or collective falling away from virtue. Such notions of corruption raised serious political questions about the health of the body politic. Just as the substance of bodies was prone to physical decay, so the moral 'substance' of the body politic was also prone to moral decay. Importantly, this implied that the corruption of morals was as inevitable as the physical corruption and decay organic bodies. This paper will explore some of the implications of this understanding of corruption by focussing on the relationship between narrow and broader notions of corruption in Western political thought. It will be argued that while there may be much to be said for interpreting corruption as the decay of virtue, it appears to be the case that contemporary narrow definitions of corruption were prefigured in older, broader understandings of corruption as moral decay.