 Various developments in Western thought have cast doubt both on the coherence of the traditional package and on the possibility that the adequacy conditions for the individual claims can be fulfilled. Foremost among these developments are the Enlightenment rejection of teleological metaphysics, the Historicist emphasis on the significance of culture for understanding human action and the Darwinian introduction of history into biological kinds. This entry aims to help clarify the adequacy conditions for claims about human nature, the satisfiability of such conditions and the reasons why the truth of claims with the relevant conditions might seem important. It proceeds in five steps. Section 1 unpacks the traditional package, paying particular attention to the importance of Aristotelian themes and to the distinction between the scientific and participant perspectives from which human nature claims can be raised. Section 2 explains why evolutionary biology raises serious problems both for the coherence of this package and for the truth of its individual component claims. Sections 3 and 4 then focus on attempts to secure scientific conceptions of human nature in the face of the challenge from evolutionary biology. The entry concludes with a discussion of accounts of human nature developed from a participant perspective, in particular accounts that, in spite of the evolutionary challenge, are taken to have normative consequences.