In the introduction to The Second Sex Simone de Beauvoir characterizes the category of the other as primordial (SS 16; DS I 16). To understand the relations between social groups, including men and women, we must follow Hegel's insight that there is “in consciousness itself a fundamental hostility to every other consciousness; the subject can be posed only in being opposed – he sets himself up as the essential, as opposed to the other, the inessential, the object” (SS 17; DS I 17). Here, Beauvoir presents a framework for explaining the relations between the sexes that makes them continuous with other human relationships. That man should strive to subjugate woman is not in itself unexpected, since it exemplifies a universal disposition also manifested in the behavior of nations and races and even in that of three travelers who share a compartment and make vaguely hostile “others” out of all the other passengers on the train (SS 17; DS I 16). What is surprising, however, is the extent of man's success. For while domination is usually an unstable and temporary achievement upset by war, potlatch, trade, or treaties, woman has been subordinate to man throughout history, and the sheer persistence of this state of affairs therefore needs to be accounted for. Beauvoir here sets out to examine a difference not of kind but of degree. Among the social relations that express the primordial dynamic between subject and other, man's domination of woman is an extreme case; it lies at one end of a spectrum of more or less persistent forms of domination (although its immutability makes it appear ahistorical), and its tenacity is what renders it puzzling.