In the 2016 Australian census, approximately 1200 people identified as transgender or gender-diverse. Even allowing for an undefined number who didn’t reveal their gender “status” on census night, the proportion of Australians in this cohort is likely to be minuscule. Statistics from other countries point in much the same direction. Why, then, have societies across the Western world experienced such a rapid and fundamental shift away from traditional understandings of gender and sex differences? Why have the sufferings of a few triggered what can only be called a revolution in policy, language, and even ontology? Why have we rejected what…