# Sensitivity to the harmony of things

## The great mathematician Alexandre Grothendieck celebrates his 80th birthday in self-imposed isolation

The most extraordinary genius in mathematics turned 80 in
March, but no parties were held. His grateful students didn’t give speeches
about him. Mathematicians didn’t convene at a grand conference in his honor. No
one even lit a candle on his birthday cake. For more than 15 years, Alexandre
Grothendieck has lived in self-imposed isolation in a tiny village in the

Nevertheless, he continues to be one of the most revered figures in mathematics. Grothendieck’s work has transformed math the way the Internet has transformed communication: Once you’re used to it, you can’t imagine what life was like before it.

“He was a master of the power of generalization,” says Luc
Illusie of

His abstractions brought concrete results. For example, Grothendieck, together with his student Pierre Deligne and others, proved the Weil conjectures, profound theorems in algebraic geometry. The conjectures are a much more sophisticated version of the startling observation René Descartes made in the 1600s that founded algebraic geometry. Descartes realized that numbers, abstractions from piles of pebbles, aren’t so different from circles or ellipses, abstractions from drawings in the sand. Equations could form a link between them, using numbers to describe curves with perfect precision. The Weil conjectures provide a vastly more complex version of that same link.

“He had an extraordinary sensitivity to the harmony of things,” Illusie says. “It’s not just that he introduced new techniques and proved big theorems. He changed the very way we think about many branches of mathematics.”

Rather than attacking a problem directly, as if pounding on a chisel to crack a nut, Grothendieck built an entire architecture of theory around the problem, so that the solution gradually became easy and natural. He likens his approach to softening the nut in water. “From time to time you rub so the liquid penetrates better, and otherwise you let time pass,” he wrote in his autobiography. “The shell becomes more ﬂexible through weeks and months — when the time is ripe, hand pressure is enough, the shell opens like a perfectly ripened avocado!”

Grothendieck was legendary for working on mathematics almost every waking moment. But he did have one interest besides mathematics: politics. His pacifism grew out of his childhood experiences during World War II.

His father, Alexander Shapiro, was an anarchist who had
rebelled against czarist

Grothendieck’s
dormant interest in politics rumbled to life in the late ’60s. He was disgusted
that the institute where he taught accepted money from the military. Hoping to
lead an insurrection of the researchers, he resigned over the matter, but none
of his fellow mathematicians joined him. When invited to give math talks, he
often spoke about politics instead. He visited

He began to have occasional rages, followed by sullen
withdrawal. He rejoined the mathematics community at a lesser university in

After he retired, he wrote a letter to 250 people declaring them part of a group chosen by God to prepare for a “New Age,” which he predicted would begin on October 14, 1996. Three months later, he sent a second letter, admitting with pain that he was no longer certain of that revelation.

In 1990, he gave away or destroyed all his papers and
disappeared into the

Pierre Lochak and Leila Schneps, two French algebraic geometers, heard from a former neighbor of Grothendieck that the “crazy mathematician” had been spotted in a nearby town. They tracked him down and found him living alone, doing organic farming. They maintained contact with him for several years, but now, Schneps says, “he’s not in a state to be visited. It’s not possible to not quarrel with him – or rather, for him not to quarrel with you.”

She hesitates to call him crazy, though she admits that in a technical sense, that might be true. “His mental state is very, very special.”

Grothendieck’s neighbors keep an eye on him, thwarting his occasional urges to eat nothing but dandelion soup, for example, and keeping Schneps and Lochak informed about his welfare.

Despite this isolation, Grothendieck continues to be a powerful presence through his mathematics. Without his advances, “it would have been impossible to attack any of the great problems in number theory and algebraic geometry that have been solved during the last 30 years,” Illusie says. Among those are Fermat’s last theorem and the Mordell conjecture.

“He had this whole thing about being buried, but it’s so
utterly false,” says David Mumford of

Jackson, A. 2004. Comme Appelé du Néant — As If Summoned from the Void: The Life of Alexandre Grothendieck, Part One. Notices of the AMS 51 (Oct.): 1038. Available at [Go to].

Jackson, A. 2004. Comme Appelé du Néant — As If Summoned from the Void: The Life of Alexandre Grothendieck, Part Two. Notices of the AMS 51 (Oct.): 1038. Available at [Go to].

The Grothendieck Circle is a project to make information available about Grothendieck’s mathematics and life. It also has a partial translation of Grothendieck’s memoir. [Go to]