It was in a dog that Sir Astley Cooper—in his 1830 Observations on the Structure and Diseases of the Testis—discovered that after an artery and vein were tied, sexual activity no longer resulted in fertilization, though the testes continued to produce sperm. But it wasn't for another sixty years that the vasectomy became regularly prescribed for remedying an enlarged prostate or bladder stones or criminal behavior (a precursor to the eugenics movement during which hundreds of thousands were sterilized worldwide). And it wasn't until the 1970s, after negative ad campaigns about the pill and a feminist demand for greater male responsibility in family planning, that the vasectomy became a more widespread form of birth control.

Today in the United States, one in six men over the age of 35 have been cut. It is the responsible thing to do, the right thing to do. I know this. The prolonged use of birth control pills may increase a woman's risk of cancer. A hysterectomy, along with the standard risks of major surgery, has such long-term psychological and physical risks as depression, hormonal imbalance, sexual pain, osteoporosis, and heart disease. Tubal ligation in women also has a much higher rate of failure (one in every 200 cases as opposed to the vasectomy's one in 2,000). Contradictory as this may seem, by getting a vasectomy, I'm manning up. At least that's what I keep telling myself.

As my appointment looms, I try to put the operation out of my head, but the world conspires to remind me—when I grill bratwursts, when I crack walnuts into my oatmeal. I have so many questions. Will my voice get higher? Will my testosterone levels drop? Will my desire fade? Will I increase my risk of prostate cancer? Will it hurt when I, you know, spooge? I wonder about what will come out of me, if anything. I suspect most men feel as I do: We like to be shooters. My doctor explains that sperm comprises only a small fraction of semen, that I might not notice a difference at all.

He looks like a doctor should: tall, athletic, gray-haired, kind-eyed. His appearance should engender trust, but all I can think is, This guy is going to tear open my junk. In his office, the fluorescent lights buzzing like wasps, he hands me a trifold brochure that explains that the sperm my testicles produce will be reabsorbed into my body. "You'll still be fertile," he says. "We're just locking the door."

He warns me that I will be awake during the procedure and that some people need a Valium to calm their nerves. Would I like one? I remember my wife waving off an epidural during the birth of our son, and in a moment of macho idiocy I say, "Nope, I'm good."

He then warns me that a vasectomy is considered a permanent procedure, that reversal is not always possible. "It is a serious decision," he says, and takes his glasses off to look at me directly. "Are you sure you're ready for it?"

···

The operating room is cold. The walls are busy with gruesome anatomical diagrams, cross sections that make the male genitalia resemble charcuterie. I lie back on the table, draw the paper sheet over my crotch, and seconds later the doctor and an older, hen-shaped nurse enter the room.

They go to work, flopping back my penis, arranging tools on a tray, positioning a stool between my legs. I squint into the blinding lights while the nurse snaps on latex gloves and my doctor shaves my scrotum. Then it's time. He warns me: In a moment, I will feel a prick like a hornet's sting—the local anesthetic. There it is, the sharpness easing into a spreading dullness. Weeks later a friend will tell me that if he had one bit of advice for someone undergoing the v-sec, it would be this: When the doctor asks if you can feel it, say yes. You get a second shot. When my doctor asks if I can feel it, I mutter something noncommittal, and he takes this as a green light and slices me open.