Hirschfeld was one of the foremost researchers in sexuality and gender in the early twentieth century. Hirschfeld was gay but never publicly came out and did not mention his own orientation in his scientific publications on sexuality. It was, after all, still illegal to be homosexual in Germany during his lifetime. He was in a long-term relationship with the archivist Karle Giese.
Later in his life, he was in a relationship with his protegee Li Shiu Tong. From the end of the nineteenth century, the study of human sexuality had begun to be approached as a scientific enterprise. Like many of his middle-class contemporaries, Hirschfeld believed that science was the best lens through which to seek to understand gender and sexuality. During the tolerant years of the Weimar Republic, Germany and Berlin in particular had a reputation of being socially progressive.
His theories were considered extremely liberal by his contemporaries. Many doctors believed that same-sex attraction should be treated like an illness. Hirschfeld, however, argued that all sexual orientations are natural because sexuality is an inborn biological characteristic that one is born with. Hirschfeld was one of the first theorists to believe that there are gender identities that lie outside of the male-female binary. Significantly, Hirschfeld believed that trans people were acting in accordance with their true nature, not against it.
He believed that they should be able to present themselves in a way that affirmed their gender identity. He thought that science should provide a means for trans people to medically transition if this is what they wished to do.
Gender refers to behaviours and roles associated with being a woman, man or non-binary that are socially constructed. This means understanding of gender can vary from society to society and can change over time.
