levi-strauss

... it is not the resemblances, but the differences, which resemble each other. By this we mean that there are not, first, animals which resemble each other (because they all share animal behavior, then ancestors which resemble each other (because they all share ancestral behavior), and lastly an overall resemblance between the two groups: but on the one hand there are animals which differ from each other (in that they belong to distinct species, each of which has its own physical appearance and mode of life), and on the other there are men - among whom the ancestors form a particular case - who also differ from each other (in that they are distributed among different segments of the society, each occupying a particular position in the social structure.)