Since de Beauvoir’s bold pronouncement that ‘One is not born a woman’ feminists have been struggling with the subject in feminist theory. Each new iteration of the subject has been advanced by its adherents as the ‘right’ definition, superseding the flawed definition that preceded it. This pattern aptly describes the reception of de Beauvoir’s subject. Feminist theorists since de Beauvoir have been disdainful of her subject, rejecting it as a tainted example of existentialism that has nothing to offer contemporary feminist theory. In this article I will challenge this judgement, arguing that de Beauvoir’s approach to the subject reveals a highly nuanced understanding of the interaction of the social, natural, and psychological. I argue that, far from rejecting de Beauvoir’s subject, we can learn much from her approach.