Once upon a time, there was sex – an obvious characteristic that branched off into female and male ways of being in the world. But genetics does not explain everything. Today we have a term to describe how, in any society, human beings experience their sexed bodies. How do we learn to become womanly or manly? How do we accept or reject the sex we are assigned at birth? And so gender comes into play. Indeed, that’s when genders come into play. This word helps us express attitudes, roles, and identities but also reveals disparities in morals and social representations. This book is a long journey from the recognition of the universal rights in Western societies to the appreciation of gender as an attributed, transformable and transferable difference. Perhaps – in the name of freedom, equality, and happiness – this journey will fundamentally alter the very nature of our species.

Giulia Sissa is Distinguished Professor of Political Science, Classics and Comparative Literature at the University of California, Los Angeles (UCLA).