The distinction between male and female, or masculinity and femininity, has long been considered to be foundational to society and the organization of its institutions. In the last decades, the massive literature on gender has challenged this discursive construction. Gender has been disassembled and reassembled, variously considered as social practice, performance, ideology. Yet the binary relationship 'man/woman' continues to be a characteristic trait of Western societies. This book gathers together contributions by experts in various fields - including law, sociology, philosophy and anthropology - to pin down the relationship between institutions and the gender binary. Centrally, it examines the way in which the present-day gender binary is shored up by the conceptualization and regulation of sex and gender at societal and institutional levels. Based on this examination, it tackles the issue of what the practices and processes of subjectivation are that preserve this binary distinction as the foundation of gender. Each of the chapters discusses this pressing question with a view to considering whether current equality policies challenge hierarchical and hegemonic understandings of gender or are the residue of a sexist understanding of gender. This analysis then paves the way for a more general and crucial question: whether institutions can, or should, contribute to the process of deconstructing the gender binary.