William Deresiewicz is an essayist, critic and the author of “A Jane Austen Education.”

CAN men and women be friends? We have been asking ourselves that question for a long time, and the answer is usually no. The movie “When Harry Met Sally...” provides the locus classicus. The problem, Harry famously explains, is that “the sex part always gets in the way.” Heterosexual people of the opposite sex may claim to be just friends, the message goes, but count on it — wink, wink, nudge, nudge — something more’s going on. Popular culture enforces the notion relentlessly. In movie after movie, show after show, the narrative arc is the same. What starts as friendship (Ross and Rachel, Monica and Chandler) ends up in bed.

There’s a history here, and it’s a surprisingly political one. Friendship between the sexes was more or less unknown in traditional society. Men and women occupied different spheres, and women were regarded as inferior in any case. A few epistolary friendships between monastics, a few relationships in literary and court circles, but beyond that, cross-sex friendship was as unthinkable in Western society as it still is in many cultures.

Then came feminism — specifically, Mary Wollstonecraft, the mother of feminism, in the late 18th century. Wollstonecraft was actually wary of platonic relationships, which could lead too easily, she thought, to mischief. (She had a child out of wedlock herself.) But she did believe that friendship, “the most sublime of all affections,” should be the mainspring of marriage.

In the 1890s, when feminism emerged from the drawing rooms and genteel committees to become a mass, radical movement (the term “feminism” itself was coined in 1895), friendship reappeared as a political demand. This was the time of the “New Woman,” portrayed in fiction and endlessly debated in the press....