Michael Sheen as Dr. William Masters and Lizzy Caplan as Virginia Johnson in the new Showtime series "Masters of Sex." (AP Photo/Showtime, Craig Blankenhorn)

“Sexual intercourse began/ in 1963/ (which was rather late for me)/ Between the end of the Chatterley ban/ And the Beatles’ first LP"  goes a famous little ditty by Philip Larkin. Maybe in Merrie Olde England. But a better argument can be made that sex was invented in 1966. The milestone was the publication of a book by two scientists. Two married scientists. Two married scientists whose research involved watching people have sex in laboratories—and then describing precisely what gave people pleasure, and how women could more efficiently do unto themselves, and couples unto one another.

How big a deal was William Masters and Virginia Johnson’s Human Sexual Response—and the 1970 followup Human Sexual Inadequacy? Well, early in 1973, when the Vietnam War ended and hundreds of prisoners of wars were repatriated from Hanoi, the Today show devoted its entire two-hour program to what a POW Rip van Winkle who went to war in 1965 and returned in 1973 would have missed: from feminism (“They walked in picket lines, they badgered congressmen, they formed pressure groups”) to the “federal legislation [that] brought the vote to 2 million more blacks,” to the serial assassinations of politicians and civil rights leaders—and, getting pride of place with all of that: Masters and Johnson. Yes, the invention of oral contraception in 1960 made it possible to women to have sex absent the consequence of pregnancy. But only to have sex. For women to demand sex as something to be enjoyed—that was Masters and Johnson’s veritable invention, and thank the Goddess for that.

I loved Thomas Maier’s dual biography of the couple Masters of Sex: The Life and Times of Wiliam Masters and Virginia Johnson, the Couple Who Taught America How to Love when it came out in 2009. I’m thrilled that Showtime has now turned the book into a miniseries. Tonight is the second episode, and in an interesting marketing strategy, you can watch the entire premier from last week on YouTube. (Viewer discretion is advised!) I loved the Maier book so much, in fact, that for the volume I’m finishing now on the politics and culture of America in the years between 1973 and 1976, I made it a priority to convey his most important theme—how profoundly his subjects changed what sex could and should mean in the contemporary world, and how much that in turn changed expectations about the balance between such fundamental issues as liberty and duty, pleasure and sacrifice, in people’s everyday lives—a real historical shift, and one that we are still reckoning with all the time.

I use those returning POWs as a case study. On the front page of The New York Times on February 5, 1973, you could meet Alice Cronin, dressed in faded hip-hugging bell-bottomed jeans and no shoes, smoking cigarettes, hair flopping loose, posing outside her San Diego home as movers unloaded the fashionable puffy white leather couch she bought “for the return of her husband, a Navy pilot held by Hanoi for six years.” But she was worried: “Mike married a very traditional wife…. Now my ideas and values have changed…. I can’t sit home and cook and clean house. I’m very career oriented, and I just hope he goes along and agrees with that…he’s missed out on a lot—liking a more casual lifestyle, being nonmaterialistic.” She hoped he understood why she didn’t trust a single thing the administration said about Vietnam. She also hoped he would go along with something else: “shifting sexual mores, the whole thing about relationships not necessarily being wrong outside of marriage. I know myself really well sexually, and he’s missed out on a good deal of that.” Knowing myself really well sexually: an unimaginable utterance before the publication of Human Sexual Response.

In the interim, thanks largely to Masters and Johnson, America had gone orgasm crazy—a development, it turned out, quite salubrious to the publishing industry. Dr. David Reuben’s Everything You Always Wanted to Know About Sex But Were Afraid to Ask was only the first pedagogical bestseller of many. (Its areas of instruction included something called “69”: “She feels the insistent throbbing of the organ against their lips and experiences a slightly salty taste, as well as the characteristic but not unpleasant odor of the sudoriferous glands of the area…. By simultaneous cunnilingus and fellatio every possible sense is brought to a fever pitch and a mutual orgasm occurs rapidly.”) Other volumes littering the bedside tables of suburban couples: The Sensuous Woman, by “J.” (it was parodied in newsweekly ads for the Japanese automobile manufacturer Datsun: “The Sensuous Car, by ‘D.”), “the first how-to book for the female who yearns to be all woman.” My Secret Garden: Women’s Sexual Fantasies, which consisted of the answers its author, Nancy Friday, had received from an advertisement she took out reading, “female sexual fantasies wanted by serious female researcher. Anonymity guaranteed.” Chapter titles included “Insatiability,” “Pain and Masochism, or, ‘Ouch, Don’t Stop!’ ” and “The Zoo.”

Couples flocked to films like Deep Throat (it made $25 million showing in seventy-three cities, despite or perhaps because of the criminal court judge in New York City who proclaimed it a “feast of carrion and squalor”), and Behind the Green Door, which began its run as the highest-grossing sex film ever at a gala Manhattan premier, the social event of the season (the projectionist showed the reels out of order; no one noticed). The cover of a book called Loving Free advertised, “For the first time, a real couple tells how they broke through their inhibitions to develop sexual excitement and joy in marriage.” Not to learn do so, men discovered, was to risk being drummed clear out of the marital bed, perhaps via a no-fault divorce. The authors had first published Loving Free anonymously, the preface explained, “because of the effect this frankness might have on the lives of their children” (“Making love standing up kills your arches!”… “Now that we’ve mentioned vibrators…”). Then they changed their mind, surprised to learn none of their children’s friends cared—being of a generation that had already relieved themselves of their sexual innocence by sneaking copies of said volumes from the nooks where their parents believed they had hidden them so well. They undertook a publicity tour, beginning in their conservative home town of Milwaukee, where they gave presentations in living rooms—what I hope were chaste presentations, for I learned from an inscribed copy (forgive me, dear siblings, for revealing this) that one of those presentations took place before my own quite square parents and their friends.

For some of those POWs it was agonizing. Sex: who could have imagined its verities could change? One of them, in an op-ed, described revisiting his old favorite cocktail lounge one Friday afternoon. “The couple at the next table were having a heated discussion which ended abruptly when the woman shouted an obscenity and commanded, ‘Buster, get out of my life.’ The red-faced dude and the attractive, though somewhat foul-mouthed, young lady turned to me…. ’You look like a nice guy. Want to come over to my apartment for a little while?’ ”

“‘I’ve got a date in an hour,’ I said.

“‘Hell, that’s plenty of time.’”

But Captain John Nasmyth was out of step in his perturbation. Researchers at the Kinsey Institute had carried out a massive new survey in 1972, learning that four-fifths of men surveyed—and no less than 100 percent of women—thought the idea of the woman initiating sex was just fine. They also found 75 percent of men and even more women thought schools should teach sexual education, that only 8 percent abjured masturbation, 85 percent approved of cunnilingus and only 5 percent of men over the age of 24 were virgins.

The aim of their work, Masters and Johnson explained in an interview the following summer in the Los Angeles Times, was to disassociate sex from sin; sexual pleasure, they said, was simply, “natural.” By 1976, even evangelicals had come (Beavis and Butthead: heh heh heh…) to agree. Beverly and Tim LaHaye (author, later, of the “Left Behind” series) published The Act of Marriage: The Beauty of Sexual Love, still in print and selling in the millions, which explained of the clitoris that God “placed it there for your enjoyment,” and excoriated the husband “who told his frustrated wife, ‘Nice girls aren’t supposed to climax.’ Today’s wife knows better.”

Showtime subscribers: learn how “today’s wife” learned—even the square ones. The rest of you: read the book.

Jessica Valenti speaks out against parental consent laws and the war against young women's bodies.