Sexual orientation refers to which gender we’re drawn to and develop romantic feelings for. The word “homosexual” comes from the Greek root “homo,” meaning “the same,” rather than the Latin “homo,” meaning “man.” It refers to both gay men and lesbians. In general, “gay” (often referring specifically to “male homosexual”) and “lesbian” are more commonly used than “homosexual,” much as is the case in Chinese. In 1988, someone borrowed the term “tongzhi” (comrade) to translate “lesbian and gay,” and from then on “tongzhi” gradually became a near-synonym for “homosexual,” marking a milestone in the founding of the Chinese-speaking world’s “tongzhi” movement (Liu Dalin, Lu Longguang, 2005).

Looking closely, we find that “homosexual” and “heterosexual” are not especially old words — they were coined by Karl Maria Benkert in 1869 (see wiki). “Gay,” on the other hand, evolved more gradually: in the late 19th century, expressions like “the gay nineties” and “gay Paree” were associated with happiness and glamour; in 1895, after Oscar Wilde’s homosexuality became public, the word “gay” took on a sexual coloring; in the 1920s, gay people began using the word among themselves, since, compared to “homosexual,” it carried less negative baggage; through the 1960s and 70s, it grew ever more common as a term for gay people.

English slang is full of terms related to homosexuality — “queer,” “dyke,” “fag,” and so on. There’s even a dedicated online dictionary of “gay slang” (A Brief Dictionary of Queer Slang and Culture), which is worth a read if you’re curious.

Let’s return to the origins of the word “homosexual.” In Plato’s Symposium (Συμπόσιου), there’s a striking passage:

… the original human nature was not like the present … The sexes were not two as they are now, but originally three in number ; there was man, woman, and the union of the two,… which had once a real existence, but is now lost, … “Androgynous” …

Here Aristophanes (189c–193e) holds that humans originally came in three sexes — male (descended from the sun), female (descended from the earth), and androgynous (descended from the moon). The Symposium is regarded as the first work in the Western tradition to discuss homosexuality, because right after this passage, Aristophanes goes on to describe these original humans as round, with four hands and four feet, two identical faces on a single head, four ears, and two sets of genitals — until Zeus split them in two, and each half was left to seek out the other.

It’s not hard to see that this account is steeped in homoerotic suggestion, and that it differs sharply from the way we categorize sex today. The word “sex” derives from the Latin “secare,” meaning “to cut” or “to divide,” which has led some to argue that the division of humanity into two sexes represents some kind of ultimate truth for our species. I’d argue that this rigid view of classification is what fueled the essentialism that ran rampant in late-19th-century thinking about homosexuality — an essentialism rooted in scientism and mechanistic reductionism. Intersex people are countless in history; to take just one example closer to home, the Ishinpō (医心方) has a passage on hermaphrodites. It says the Chinese believed some women’s clitorises grew larger with the full moon, and that during the full moon such a woman had to have intercourse with a woman or she would die; during the new moon, she had to have intercourse with a man or face the same fate (R.H. van Gulik, 1990). Intersex figures appear widely across literature, conveniently satisfying readers’ appetite for the exotic.

The concept of the “intersex” gave rise to a whole series of “inventions” at the turn of the 19th and 20th centuries. Amid two wars and breakneck economic growth, people grew psychologically alienated. Many insisted that the First World War was responsible for the collapse of young people’s sexual morals — which is wrong, since there was already plenty of sexual ferment before it. As Ian Hacking put it, “a kind of person comes into being at the same time as the kind itself is invented. In some cases, our classifications and our own kinds emerge hand in hand, reinforcing one another” (Angus McLaren, 2007). What we can say with confidence is that, at the turn of the 19th and 20th centuries, people could no longer make do with just two sexes, and a number of new terms — “homosexual” among them — were born alongside concepts like masochism and sadism.

In that era, homosexuality was defined and explained in wildly wrongheaded ways. Most sexologists put it down to degeneracy and dissipation, and went hunting for absurd physical “proof” — A. Tardieu, for instance, told readers that “active” homosexuals had unusually thin, dog-like penises, while “passive” homosexuals had funnel-shaped anuses. Later scholars gradually came to understand that homosexuality, if it was a “disorder” at all, resided in the nervous system rather than the body… Given the dark history the word “homosexual” grew up alongside, it’s no wonder it never won much favor among gay people themselves.