More than a century ago, Dr. Magnus Hirschfeld first argued that gender and sexuality were fluid. Dubbed “the Einstein of Sex,” Hirschfeld grew famous (and infamous) for his liberating theory of sexual relativity. Today, he’s been largely forgotten. Journalist Daniel Brook reinvigorates Hirschfeld’s legacy, recovering one of the great visionaries of the twentieth century. As an advocate for trans acceptance and the decriminalisation of homosexuality, Hirschfeld served as intellectual impresario to Weimar Berlin’s libertine cabaret culture. Driven from his homeland by fascists, he embarked on a global survey of human sexuality and witnessed the diversity of gay life, as well as the impacts of imperialism and racism firsthand. Hirschfeld spent his final years in exile, working to debunk Nazi race science and warn the world of the genocidal dangers of racism. Rich in passion and intellect, The Einstein of Sex at last brings together this unsung icon’s work on sexuality, gender, and race and recovers the globe-trotting visionary who first saw beyond the binaries.