The privilege of ethnology and psychoanalysis, the reason for their profound kinship and symmetry, must not be sought, therefore, in some common concern to pierce the profound enigma, the most secret part of human nature; in fact, what illuminates the space of their discourse is much more the historical a priori of all the sciences of man those great caesuras, furrows, and dividing lines which traced man's outline in the Western episteme and made him a possible area of knowledge.