It was a modest little goal, for which I was happy to shell out $50, and sit in a cavernous arena with countless retired jerseys of New York Knickerbockers and Rangers hanging above my head, to listen to some of the most personal revelations about what happens “down there” — the kind of thing I’m more used to hearing about in groups of two.

Pardon me for quibbling about something so utterly, totally politically correct, but memo to Eve: three-and-a-half hours with no intermission? Even feminists have to pee. Especially when, even on this V-for-very special night, the Garden’s concession stands sold the usual V-for-vile hot dogs, nachos and supersize beers. And, you know, it’s not that I didn’t enjoy watching Glenn Close fall to her knees in her hot-pink pantsuit, shrieking “Cunnnnnttttt!!!” but it will really feel like we’ve come a long way (baby) when a big movie star can say the word “cunt” and not make thousands of women giggle and cheer.

Another thing, Eve: Are you aware of what your corporate sponsors (even vaginas, apparently, can get corporate sponsors these days) are doing? You heaped praise upon Lifetime, the cable television network, telling us it was proud to stand for stopping violence against women. But did you happen to catch, the night before V-day, Lifetime’s showing of that feel-good feminist classic “The Silence of the Lambs”?

And if those charitable folks at Tampax (nice synergy, Eve!) are serious about making the world safe for vaginas and the women who own them, why do they perpetuate the myth that there’s something, well, icky about tampons? When my supersize beer had taken up residence in my bladder and I just couldn’t wait any longer, I made a trip to the ladies room. On my way in, two nice young women offered me a freebie: a little box, wrapped prettily in shiny blue foil with yellow and white flowers and a sticker that said “Cool Gift Inside.”

At first I thought it was a Rice Krispies Treat. But it turned out to be a sample of Tampax Compak tampons, which, according to the ad copy inside, provide “Protection and Discretion in the Palm of Your Hand.” The two free tampons were inside a stylish jet-silver “Purse-Pak,” which was inside a cardboard box, which was inside the blue foil wrapping. In other words, at center stage in Madison Square Garden, members of a vulva choir were talking very loudly and very clearly about snatches, pussies, hoochies and every word you could possibly think of for “vaginas” while, at the same time, Tampax was handing out small, discreet, heavily concealed — shh! — tampons? Eve: tampon, TAMPON or, as Close might put it, “TAMMMPONNNNN!”

Inside the ladies room, the walls and stalls were papered with Tampax promotional posters saying, “Tampax: The Revolution Continues.” You want a tampon revolution? I’ll give you a tampon revolution: How about a box of supers for half the price I pay now? (I actually think I have a good idea for lowering the price of so-called feminine protection: Let’s designate a tampon- and napkin-free week during which every woman in America who is menstruating simply refuses to wear anything to catch the flow. The men that run the corporations that make these darn things will be giving ‘em away in no time.)

Shortly after V-day, two things happened as if by design, as if to remind me that it doesn’t have to be this way — with corporate sponsors promoting shame along with their products and multimillion-dollar movie stars gathering in a sports arena on a Saturday night, along with thousands of women, for a high-gloss event that links sex with violence instead of pleasure.

First, I read that Dr. William Masters had died. Here was a man — a churchgoing Episcopalian and a registered Republican — who, with Virginia Johnson, had devoted more than half a century to taking the mystery out of sex and making sex more pleasurable. Masters and Johnson were profoundly controversial, sometimes wrong, but always profoundly influential. Their goal was to bring sexual joy to the masses, and they did that, especially for women.

Second, shortly after V-day I discovered a new book whose approach is the antithesis of the coy and infuriating marketing campaign for the tampon that dare not speak its name. The book is “The Clitoral Truth: The Secret World at Your Fingertips” by Rebecca Chalker, a longtime women’s health activist, medical writer and sexologist. Women’s sexuality is not about the vagina, Chalker says. (So get over it, Eve.) Her book blows the lid off some of the biggest secrets being kept from women and their partners about women’s sexual pleasure and how to achieve it. The clitoris, Chalker tells us (and shows us, with drawings by Bay Area illustrator Fish), is the one part of the female body whose sole purpose is pleasure. It is, she explains, so much more than that pea-size, exquisitely sensitive bundle of nerves we think it is.

Drawing on her earlier work with the Federation of Feminist Women’s Health Centers and its groundbreaking 1981 book “A New View of a Woman’s Body,” Chalker shows that the clit really is a “system” of 18 distinct but interrelated parts. In the chapter “The Case of the Missing Clitoris,” Chalker details just how it came to be that, after 2,500 years in which the clitoris and the penis were considered coequals, so much information and knowledge about the clit just happened to get lost.

Chalker devotes an entire chapter to sorting out the facts, fiction and fantasy about so-called female ejaculation. She also details how women can expand their repertoire of sexual experiences and satisfaction by going beyond “the intercourse model,” and includes her own and others’ firsthand accounts of full-body pleasure workshops with names like “Body Electric” and “Sluts and Goddesses.”

“The Clitoral Truth” is “Our Bodies, Ourselves,” your favorite history textbook, a Nancy Drew mystery and the Good Vibrations erotica catalog rolled into one small volume (with a knockout cover). The book is personal as well as political — pro-masturbation but not anti-partner, pro-woman but not anti-man (although one can only imagine how most men would react to her statement that “men must be willing to learn some degree of ejaculatory control”).

Salon spoke with Chalker at her fifth-floor walk-up apartment in Manhattan.

Why don’t you do “The Clitoris Monologues”?

I just might.

If your clit could talk, what would it say?

I guess it would say, “Get me out of here! Get me out of this obscurity that I’ve lived in for millennia! I’m alive!”

Sounds like you want to take the clit out of the closet.

Yes. It’s been closeted, and denigrated. It’s pretty obvious that people still have a very hard time saying the C-word. I wrote this book to reclaim the clitoris. I wrote it to reveal the unknown extent and power of the clitoris, to raise it from this obscure, pea-size organ that we think of it as, to make the world safe for women’s sexuality.

When I’ve mentioned the title of your book, the first thing several people have said is, “Is that a book about masturbation?”

No. Not exclusively, anyway. The focus of this book is to help women understand, explore and expand their sexual response. Certainly masturbation is a bedrock of that. But the book is not about how to masturbate.

So what is the clitoral truth?

The clitoral truth is that women’s sexuality is more powerful and compelling and complex and unknown than has been acknowledged. The clitoris is as extensive as the penis. In fact, the clitoris and the penis are almost identical in their parts. They’re just arranged differently. Up until about eight weeks of gestation, all fetuses appear to be female. Then, in fetuses with X-Y chromosomes, which designates them as male, testosterone kicks in and the parts are rearranged. In females the parts continue to grow into what is really an extensive clitoral system. So literally, the penis is a derivation of the clitoris, not the other way around, and they’re equal. It’s just that the penis is outside, and can be easily seen.

So the clitoris is a lot more than what meets the eye?

Absolutely! Or the hand. It’s an organ system. There are parts that can be seen and felt, and there are parts that cannot be seen. There’s erectile tissue, for example, that fills with blood during sexual response. There are two parts that look like the wishbone of a chicken. And there are two large bodies of erectile tissue called bulbs, directly under the inner lips. There’s the urethral sponge, the spongy erectile tissue that surrounds the female urethra, just as it does in the penis. This is the location of the so-called G spot. There are also three layers of muscle underneath it all, and the muscles are critical in causing the spasm of orgasm. There are blood vessels, which bring the greater blood flow to the clitoris, and there are nerves, which carry the sensory signals between the clitoris and the brain and back.

Why is it that so many women, who are, after all, the owners of the clitoris, don’t know this?

It’s not just that women know so little about the clit — the medical profession knows little about it also. The reason is that women’s sexuality has been devalued in various ways over time. The ancient Greeks knew precisely that women’s and men’s genital anatomy was similar. Aristotle wrote about it, and Claudius Galen, the most famous physician of the Greek era, said that women are just men turned inside out. Galen’s works were the gold standard of medical understanding up to and throughout the Renaissance. In fact, in the 17th century, midwives recommended that women have orgasms to help them get pregnant, for general health and well-being and to keep their relationships healthy.

Ah, this is where you have unraveled a whodunit.

Yes. In the 18th century, around the time of the French Revolution, when women began to demand some measure of social and economic equality, we suddenly see women’s sexual response and anatomy and orgasm begin to be downplayed. For the first time, the leading philosophers and physicians of the day classified women’s sexuality, and their ability to menstruate and become pregnant, as a disability. From then on we see parts of the clitoris being left out of medical illustrations — literally erased — or being ascribed to the reproductive or urinary tract. All except for the little pea-size glans.

It sounds like a clit conspiracy, or maybe a coverup.

Yup. In the Victorian era, we see the first debate about whether orgasm for women is even necessary. And then Freud came along and said that the clitoris is a child’s plaything, and the vagina is the focus of mature women’s sexuality. Freudianism gripped the view of women’s sexuality almost throughout the 20th century.

You want women to understand that the clitoris is really the key player in women’s sexual pleasure. So is the vagina dead? Is it irrelevant, over?

As I say in my book, sex is not about the vagina. But no, we can’t just forget about the vagina. It provides this nice, tight, warm little pocket that is designed to promote male orgasm, and therefore pregnancy, and therefore the carrying on of the species. But the vagina does not work that well for women in terms of giving the clitoris the kind of stimulation that it needs.

When it comes to clits, does size matter?

No, the size of the clitoris doesn’t matter in being able to experience sexual response.

Are lesbians closer to the clitoral truth than heterosexual women are?

I think so. Because sex has been totally defined through male standards, lesbians have slipped under the radar, and they’ve been able to teach themselves and discover for themselves what feels good and what works in sex. Throughout history, lesbians have been ignored — or their existence has been denied. So they’ve existed in a secret world where they developed their own standards and sexuality.

In your book, you dive right into the controversy over female ejaculation.

The world is divided into two camps: those who believe it happens, probably because they’ve experienced it themselves or they’ve seen it occur in their partners, and those who don’t believe it happens. I’ve found references to female ejaculation in the first sexual advice books that were written in China, in 500 B.C. The phrase is “Her vulva floods.” You see these metaphors throughout history. So I thought, “This is ridiculous. We have this long history of references to female ejaculation. We have a lot of research that was initiated in the 1980s.” I just put it all together into a single chapter. Some women produce gushes of fluid; others produce little dribbles or drops; some produce none. I do not want to hold up female ejaculation as another performance standard for women, or say that it’s something men have to elicit in order to be successful. I just want the subject cleared up.

Why do you say that people should stop focusing so much on orgasm?

Orgasm is one of the possible outcomes of sexual activity. It is not the only successful outcome.

Isn’t that going to be a hard sell?

It is. Look, sexuality in our society has been defined entirely through the male standard: stimulation, erection, ejaculation. But there’s another way to do it, and it’s the oldest way in the world. Sexuality is the foundation of tantra and Taoism, which [are among] the world’s first religions. The focus was extended sexual sessions that were seen as leading to enlightenment. Women’s sexual response was highly valued, and men had to learn ejaculatory control so that women had a chance to have as many orgasms as they wanted. A man failed if he did not provide a woman with the opportunity to have the sexual pleasure she wanted. There are other ways to practice sex that benefit everybody, women and men.

You say in your book that men today need to learn some form of ejaculatory control. I read that and I thought, “Yeah, this is going to go over really big.”

I totally agree that it’s the toughest sell on the planet, and I don’t really know what we’re going to do about it. But men are really missing out on great pleasure. For women and men, learning full-body sexual response can be mind-blowing, orgasm or not. And it often results in a knockout orgasm for men and multiple orgasms for women, not to mention deeper intimacy.

But what about the good old-fashioned quickie?

There’s definitely a place for that, too. You might call those “maintenance orgasms.” It’s really like junk food or fast food. I guess they’re OK. I mean, you gotta eat, right?

Ashcroft, a professor of physiology at Oxford University in England, combines personal narrative, tales of derring-do and, most of all, accessible scientific explanations to describe what happens when human beings push themselves to their limits — when they succumb to the overpowering urge to climb high, dive deep, run fast, immerse themselves in unbearable heat or cold and venture into the mysterious and dangerous realm of space.

She writes of men and women who have succeeded, and of those who have failed. She answers the questions that have plagued you for years, like: Why don’t sperm whales get the bends when human divers do? Why can some human beings climb Mount Everest without extra oxygen while passengers in a plane that depressurizes at the same altitude stand no chance of survival? And what is the Vomit Comet?

And she writes of scientists and researchers who sometimes put their lives on the line (usually because they couldn’t convince anybody else to do so) to solve some of the riddles of human survival. There was, for example, Sir Charles Bladgeon, who, in the 18th century, walked into a room heated to 105 degrees C (221 F) with some eggs, raw steak and a dog. Within 15 minutes, the steak and eggs were cooked to perfection; Bladgeon and the dog, fortunately, were not.

Ashcroft herself is no stick-in-the-mud. She has experienced some of the extremes she documents, including immersion in superhot Japanese baths, altitude sickness climbing Mount Kilimanjaro and the terror of her first deep-sea dive. Talking with Salon by telephone from London must have seemed like child’s play by comparison.

The book’s cover has a sort of eerie photo of diving women. What’s that about?

Ah, yes, the Ama women of Japan. They’ve been around for 2,000 years. It’s such an onerous profession. They’re diving for abalone and shellfish and for the mother-of-pearl shells. The highly trained ones, the funado, dive to about 20 meters [66 feet] deep. They have a large weight attached that enables them to go down to the bottom. They dive down with a rope tied around their waist, and they have a small basket that they fill with the prime delicacies of Japan. And then a male assistant hauls up the basket, and the woman may fill more baskets, depending how long she can hold her breath. Then she’s pulled up to the top by the assistant. At that depth, you do need someone to help you up, because as you dive, the air in your lungs compresses and you tend to sink.

One lady-in-waiting at the court of the Japanese empress a thousand years ago described the fact that the women are the ones doing all the work. They are diving down into the cold, having to hold their breath, and then come up sputtering and choking. Meanwhile, the men who are their partners sit in their little boats on the surface of the water, drinking and telling jokes and laughing and talking to all the other men, and generally having a good time.

Why do some of us prefer the comfortable middle, and others seem to have a real thirst for life at the extremes?

I think that there are two different sorts of people — those who do it for the kicks, the adrenaline thrill, and those who do it because they find it interesting and fascinating. I’m one of the latter. The challenge of going up a mountain or looking at landscapes you’ve never seen before, is just exhilarating. I’d love to go into space and look down on Earth and space, wouldn’t you?

No, I think it would be quite frightening! Talk about some of the extremes that you have gone to.

Personally speaking, I’m a wimp. I do things I think are interesting and exciting, but I have never really put myself in any danger. I have climbed to the top of Kilimanjaro. I have done a little scuba diving. I have been in very cold and very hot environments. But we all put ourselves in conditions where there are physical challenges to us; it’s just that we don’t necessarily notice them. All of us fly in airplanes, and if the plane depressurized, we would have a big problem. There are many things that we need to do, and we have engineered our environment so that we can survive without difficulty.

Without meaning any disrespect, what’s exhilarating about feeling, on the top of Kilimanjaro, like your head’s going to blow off from altitude sickness, as you describe in the book? To be honest, when you are in an extreme situation, you’re not really thinking of the scientific explanations, are you? Aren’t you just thinking, Get me out of here?

If you’re a scientist, you see things on many different levels. I do think, I don’t want to be here; let’s get out of here. But at the same time, my brain is saying, What’s going on, what’s working, what can I do to make this better, how can I behave? And at the top of Kilimanjaro, the view is wonderful! There you are, and you have ice fields on the equator!

Is there an extreme you wouldn’t go to?

The people I admire most of all are firefighters. I’m afraid of fire. The whole idea of walking into a firestorm — that to me is so scary I just couldn’t bear to do it. My recurrent nightmare is running down a road engulfed in flames.

Back to airplanes for a minute. I’m a fearful flier, and your explanation of sudden depressurization made me wonder whether those oxygen masks would really do the trick.

These things are very dramatic, but they happen very rarely. There’s a reason you’re told to put on your oxygen mask before you put it on your child — if the cabin really depressurizes, you’ll be rather woozy before you’re even able to put it on your child. Once there was a blowout on a British Airways plane, where the window actually blew straight out, and the captain was actually sucked out. The reason he got sucked out, of course, is because he wasn’t wearing his safety harness.

So it all comes down to wearing your seat belt?

Absolutely.

You’re saying, if you were in a passenger plane at 35,000 feet, and the window blew out right next to you, and you had your seat belt on, you wouldn’t be sucked out of the plane?

You probably wouldn’t be. But all the things sitting on your lap would be.

That seems like a small sacrifice.

The other thing, of course, is that the windows on an aircraft are deliberately small. There is a trade-off between passengers who want to see what’s outside and stopping things and people from being sucked out if there is a blowout.

I don’t think I can talk about this anymore. Let’s switch gears. Life at the extremes seems to run in your family. In your chapter about life in the extreme cold, you tell the story of how your own grandfather, who was sick and wounded, survived quite an ordeal during World War I. After his ship was torpedoed, he somehow survived many hours, semiconscious, in freezing cold water. How do you explain his not succumbing to hypothermia?

First of all, he was quite a fat man. The fatter you are, the more insulated you are and the better you do. Second of all, the thing you shouldn’t do when you are in cold water is splash around and make a lot of movements. All those movements dissipate the water that is next to your body, which is warmed up by your body, so you do best if you just try to float. My grandfather was strapped to a stretcher, so he couldn’t move at all. And the third thing was, he was running a severe fever, so he was generating a lot of heat, which kept him warm, I think.

I think we’re developing a theme here. If you are fat and strapped in, you have a better chance of surviving air and sea emergencies.

Yes.

It’s fascinating that so many scientists and researchers have gone to real extremes themselves to answer questions about just how much human beings can endure. My personal favorite in the book is the British scientist who purposely put himself into convulsions to test the effects of gases on the human body at pressure. His work transformed modern underwater-diving practices.

Oh, yes, J.B.S. Haldane. One of the things that happened to him in his pressure chamber is that he got nosebleeds, and he wasn’t very tidy, so he sort of dripped along the corridor. Yes, he was quite extraordinary. You have to remember that some of these experiments were carried out during the Second World War, and during war, people are much less concerned about taking risks because other people are dying all around them. So, for example, there were scientists who actually went down underwater, having calculated the safe distance from an underwater explosion, and had somebody detonate the explosion and then check that they were safe. That’s what you have to do. You can’t expect volunteers to do things you haven’t done yourself.

Do you know what you’re going to put your own body through next?

What I’d really love to do — the one real extreme I’d like to try — is fly in the Vomit Comet.

The what?

The Vomit Comet. It’s used for training astronauts. It flies a parabola. It alternately dives and climbs in the sky. When it dives, you become weightless. And when it climbs, you get two times the force of gravity on you. A lot of people say it makes them sick.

OK, you’ve explained what happens when man goes into space, when man dives under the sea; you’ve explained how people can withstand incredible heat and cold. So now tell me this: How come nobody can make a decent cup of decaf coffee?

[Laughs] Scientifically, if you think about it, the question is how to get out the caffeine without ruining the flavor. I think it’s actually not a trivial question. It’s tricky. Some problems are just really difficult.