This is an extremely broad topic, and one that overlaps with many of the subjects considered already. For example, a society’s conception of sexual difference can be considered as part of its ‘culture’, and certainly many of the theories discussed here, if accepted as persuasive, have implications for our understanding of ancient gender relations. The process is not necessarily one-way, as theories contest one another’s claims to be ‘fundamental’; this chapter should be read against earlier ones, and vice versa. Sociobiology argues that sexual discrimination is founded on biological difference; feminists might respond that a patriarchal society naturally produces a sexist biology. Marxists claim that culture in general ‘reflects’ the underlying structures of production; Freudians might note instead the way that aspects of production-the capitalist drive to accumulate, for example-can be understood in psychological terms, a persistent survival of the ‘anal’ stage in libidinal development, in which the infant obtains pleasure by ‘hoarding’ its faeces —while Marxism’s denunciation of capitalism merely expresses latent hostility towards the tyrannical father-figure.