On the whole, Western society is organised around the assumption that the differences between the sexes are more important than any qualities they have in common. When people try to justify this assumption in terms of ‘natural’ differences, two separate processes become confused: the tendency to differentiate by sex, and the tendency to differentiate in a particular way by sex. The first is genuinely a constant feature of human society but the second is not, and its inconstancy marks the division between ‘sex’ and ‘gender’: sex differences may be ‘natural’, but gender differences have their source in culture, not nature. Much of the confusion in the debate about sex roles comes from the fact that we tend to speak of ‘sex differences’ when we are really talking about differences of gender. Because of this the rationale of a society organised around sex differences is never made clear and the idea of a society based on liberation from conventional gender roles is written off as an impossibility.