A basic topic of ethics, different accounts of which underlie such different conceptions of human life as that of the classical Greeks and of Christianity. A preoccupation of Enlightenment philosophy was to find a constant human nature beneath superficial differences due to culture and society. The common core would contain sufficient natural sympathy with others, benevolence, perception of self-interest, and capacity for acquiescing in just institutions, to provide a foundation for a purely secular ethics. This hope was dashed by the Hegelian perception of human beings as only possessing natures that are moulded by their historical and social circumstance. However, it then recurs at a higher level, with the thought that we have natures that make us capable of some political and social arrangements under which we flourish, and incapable of others. See essentialism, sociobiology, evolutionary psychology.