A terrible sin, a gift from the gods, a mental illness, a natural human variation—over the centuries people have defined homosexuality in all of these ways. Since the word homosexual was coined in 1869, many scientists in a variety of fields have sought to understand same-sex intimacy. Drawing on recent insights in biology and genetics, psychiatrist Francis Mondimore set out to explore the complex landscape of sexual orientation.

The result is A Natural History of Homosexuality, a generous work that synthesizes research in biology, history, psychology, and politics to explain how homosexuality has been understood and defined from ancient times until the present. Mondimore narrates tales of love and courage as well as discrimination and bigotry in settings as diverse as ancient Greece and Victorian England, early America and fin de siecle Vienna. He also tells fascinating stories about societies which accepted, incorporated, or institutionalized homosexuality into mainstream culture, stories illustrating that same-sex eroticism was often accepted as a normal aspect of human sexuality. In twentieth-century America, researchers first recognized that homosexuality might not be "pathological" when Alfred Kinsey and Evelyn Hooker conducted the first studies of sexuality not biased by preconceived notions of "normal" sexual behavior.