The Canon: Sexual Behavior in the Human Male/Sexual Behavior in the Human Female. By Alfred Kinsey (with Wardell B. Pomeroy, Clyde E. Martin and Paul Gebhard)

Alfred Kinsey was a taxonomist obsessed. Having already made his mark in the study of gall wasps, he later turned to the study of human sexual behaviour after being asked to teach a marriage guidance course at Indiana University in Bloomington. The publication of the two Kinsey Reports (on male behaviour in 1948 and female behaviour in 1953) would steep his life in controversy, and he became a figure of hate to many.

Ultimately, he provided about 18,000 sexual life stories - personally interviewing more than 7,000 people in long and challenging interviews. He was the orgasmic bookkeeper who counted who did what with whom when, where and how often, logging all into his confidential coding boxes. Above all, he showed how sex is social, shaped by class, age, religion and gender (he was less hot on race, his sample being exclusively white).

Most significantly, he uncovered a vast, hidden world of variant sexual behaviour: what people said and did were two different things. He found the near-universality of male and female masturbation; a wide prevalence of sex among the young; common enough premarital and extramarital intercourse; a lot of anal sex, fellatio and zoophilia; and, famously, high rates of homosexual behaviour. The "norm" of marital intercourse was overshadowed as Kinsey estimated that, given the law, 95 per cent of US citizens could be imprisoned for what they did in bed!

The first edition of Sexual Behavior in the Human Male sold more than 400,000 copies - unheard of for a scholarly book. Most academic work has a minuscule impact, but Kinsey's made private things public and shocking things commonplace: Western sexuality would never be the same.

There were fierce attacks from moralists, but there were more thoughtful critiques, too: Lionel Trilling famously argued that Kinsey's focus on sexual behaviour reduced sex to orgasm-counting and robbed it of human meaning; methodologists queried his sampling; later, feminists would criticise his tacit celebration of male power. But for good or ill, the mark of Kinsey is everywhere in modern culture.

I first read Kinsey as an undergraduate in 1966 - his work was recommended for its detailed, if flawed, methodology. It was hardly a fun read, riddled as it was with tables and the jargon of objectivity. But as a young gay man, I found the section on homosexuality life-changing: I realised I could not be all alone when Kinsey told me that some 37 per cent of men had reached orgasm with another man.

Suggesting Kinsey could be part of the Canon raises the question of just what such a canon could be, as many will object to its inclusion. But, to peddle cliches, no book is an island: each stands on the shoulders of giants. There was Sigmund Freud, Henry Havelock Ellis and Magnus Hirschfield before it; now we have Michel Foucault, feminism, Shere Hite, sex therapy, queer theory and the Aids research industry. But Kinsey started it: he was the great demystifier of sex and helped create a new language of sexualities.