The four most overrated things in life, Christopher Hitchens once said, are “Champagne, lobsters, anal sex and picnics.” This remark was repeated at his memorial service this past April in New York City. The next speaker was the British comic Stephen Fry, who is out and proud. “Well,” he commented, “three out of four isn’t bad.”

In his new book, “How to Be Gay,” David M. Halperin agrees, at least on one unlikely level, with Hitchens. Mr. Halperin, a professor of the history and theory of sexuality at the University of Michigan, Ann Arbor, provocatively argues that when it comes to defining what it means to be a homosexual man, sex is overrated. Culture matters more.

“Gayness,” Mr. Halperin declares, “is not a state or condition. It’s a mode of perception, an attitude, an ethos: in short, it is a practice.” The great value of traditional gay male culture, he further posits, perhaps even more challengingly, “resides in some of its most despised and repudiated features: gay male femininity, diva worship, aestheticism, snobbery, drama, adoration of glamour, caricature of women and obsession with the figure of the mother.”

These declarations run counter to much of the prevailing gay pride ethos, which argues that gay men are, to borrow the title of Andrew Sullivan’s 1995 book, “virtually normal.” Pretty much like straight people, that is, except for what they do with their dangly bits. To this ethos Mr. Halperin, like the figure on the Heisman Trophy, raises his hand in rebuff: “For all its undeniable benefits, gay pride is now preventing us from knowing ourselves.”