Thomas Hobbes changed the face of moral philosophy in ways that still structure and resonate within the contemporary debate. It was Hobbes’s central aim, particularly as expressed in the Leviathan, to make moral philosophy genuinely ‘scientific’, where this term is understood as science had developed and evolved in the first half of the seventeenth century. Specifically, it was Hobbes’s aim to provide a thoroughly naturalistic description of human beings in terms of the basic categories and laws of matter and motion. By analyzing the individual and society in these terms, Hobbes proposed to identify and describe a set of moral laws that are eternal and immutable, and can be known to all those who are capable of reason and science (L, 15.40). Even more ambitiously, it was Hobbes’s further hope that these ‘theorems of moral doctrine’ would be put into practical use by public authorities with a view to maintaining a peaceful, stable social order (L, 31.41).