Reprinted From the New York Times

What’s life for? That question stirred as I contemplated two rhesus monkeys, Canto, aged 27, and Owen, aged 29, whose photographs appeared last week in The New York Times.

The monkeys are part of a protracted experiment in aging being conducted by a University of Wisconsin team. Canto gets a restricted diet with 30 percent fewer calories than usual while Owen gets to eat whatever the heck he pleases.

Preliminary conclusions, published in Science two decades after the experiment began, “demonstrate that caloric restriction slows aging in a primate species,” the scientists leading the experiment wrote. While just 13 percent of the dieting group has died in ways judged due to old age, 37 percent of the feasting monkeys are already dead.

These conclusions have been contested by other scientists for various reasons I won’t bore you with — boredom definitely shortens life spans.

Meanwhile, before everyone holds the French fries, the issue arises of how these primates — whose average life span in the wild is 27 (with a maximum of 40) — are feeling and whether these feelings impact their desire to live.

Monkeys’ emotions were part of my childhood. My father, a doctor, worked with them all his life. His thesis at the University of Witwatersrand in Johannesburg, South Africa, was on the menstrual cycle of baboons. When he settled in Britain in the 1950s, he had some of his baboons (average life span 30) shipped over, ultimately donating a couple to the London Zoo.

Upon visiting the zoo much later, he got a full-throated greeting from the baboons, who rushed to the front of their cage to tell him they’d missed him. Moral of story: Don’t underestimate monkeys’ feelings.

Which brings me to low-cal Canto and high-cal Owen: Canto looks drawn, weary, ashen and miserable in his thinness, mouth slightly agape, features pinched, eyes blank, his expression screaming, “Please, no, not another plateful of seeds!”

Well-fed Owen, by contrast, is a happy camper with a wry smile, every inch the laid-back simian, plump, eyes twinkling, full mouth relaxed, skin glowing, exuding wisdom as if he’s just read Kierkegaard and concluded that “Life must be lived forward, but can only be understood backward.”

It’s the difference between the guy who got the marbleized rib-eye and the guy who got the oh-so-lean filet. Or between the guy who got a Château Grand Pontet St. Emilion with his brie and the guy who got water. As Edgar notes in King Lear, “Ripeness is all.” You don’t get to ripeness by eating apple peel for breakfast.

Speaking of St. Emilion, scientists, aware that most human beings don’t have the discipline to slash their calorie intake by almost a third, have been looking for substances that might mimic the effects of caloric restriction. They have found one candidate, resveratrol, in red wine.

The thing is there’s not enough resveratrol in wine to do the trick, so scientists are trying to concentrate it, or produce a chemical like it in order to offer people the gain (in life expectancy) without the pain (of dieting).

I don’t buy this gain-without-pain notion. Duality resides, indissoluble, at life’s core — Faust’s two souls within his breast, Anna Karenina’s shifting essence. Life without death would be miserable. Its beauty is bound to its fragility. Dawn is unimaginable without the dusk.

When life extension supplants life quality as a goal, you get the desolation of Canto the monkey. Living to 120 holds zero appeal for me. Canto looks like he’s itching to be put out of his misery.

There’s an alternative to resveratrol. Something is secreted in the love-sick that causes rapid loss of appetite — caloric restriction — yet scientists have been unable to reproduce this miracle substance, for if they did they would be decoding love. Because love is too close to the divine, life’s essence, it seems to defy such breakdown.

My mother died of cancer at 69. Her father lived to 98, her mother to 104. I said my mother died of cancer. But that’s not true. She was bipolar and depression devastated her. What took her life was misery.

We don’t understand what the mind secretes. The process of aging remains full of enigma. But I’d bet on jovial Owen outliving wretched Canto. I suspect those dissenting scientists I didn’t bore you with are right.

My 98-year-old grandfather had a party trick, making crisscross incisions into a watermelon, before allowing it to fall open in a giant red blossom. It was as beautiful as a lily opening — and, still vivid, close to what life is for.

When my father went to pick up his baboons at Heathrow airport, he stopped at a grocery store to buy them a treat. “Two pounds of bananas, please,” he said. But there were none. “O.K.,” he said, “Then I’ll take two pounds of carrots.” The shopkeeper gave him a very strange look before hurriedly handing over the carrots.

I can hear my 88-year-old father’s laughter as he tells this story. Laughter extends life. There’s little of it in the low-cal world and little doubt pudgy Owen will have the last laugh.