This article is taken from the February 2022 issue of The Critic. To get the full magazine why not subscribe? Right now we’re offering five issue for just £10.

In the wake of the Second World War, John von Neumann, one of the scientists who had helped build the atom bomb, was convinced that war with the Soviet Union was coming. He advocated a pre-emptive strike by the US. “If you say why not bomb them tomorrow, I say why not today?” he said. “If you say today at five o’clock, I say why not one o’clock?”

His argument, which made him one of the inspirations for Stanley Kubrick’s Dr Strangelove, was that of the cold-eyed rationalist. Having seen the destruction wrought on his native Hungary by the war that had just ended, he wished to protect his new home, America, from similar harm. A quick war would, he and many others thought, minimise overall human suffering by wiping out Soviet forces before they had time to do harm.

A few years later, when von Neumann was dying of cancer and deeply upset about it, his daughter challenged him: “You contemplate with equanimity eliminating millions of people, yet you cannot deal with your own death.”

“That’s entirely different,” he replied.

Ananyo Bhattacharya’s biography of von Neumann has a similar difficulty moving between the perspectives of vast historical sweep and the personal and intimate, a result of the huge ambition of the book.

There are particular challenges in writing the biography of a genius

Von Neumann, the man, proves hard to pin down, but Bhattacharya succeeds in arguing that von Neumann, the genius, is under-appreciated, and that to understand him, we have to see him in the context of the political and scientific movements of his time.

There are particular challenges in writing the biography of a genius. Sometimes their brilliance was a revolutionary insight that now seems commonplace, and the difficulty is in illustrating that this was not always so. In other cases, everyone can see that the person in question was very clever, so much so that few can understand what it was that they did. This, it turns out, is the problem with von Neumann.

That he deserves to be better known can’t be disputed. He was one of the generation of mathematicians and physicists in the first half of the twentieth century who revolutionised our understanding of the world and who, by splitting the atom, established the pattern of global politics for the second half. He was part of the Jewish exodus from Europe that followed the rise of the Nazis, invited, alongside Albert Einstein, to be one of the first resident scholars at Princeton’s Institute for Advanced Study.

And he was as brilliant as any of them, making contributions in fields from pure mathematics to quantum mechanics to explosives to nuclear physics to computer science to game theory to artificial life. Each of these subjects could sustain a book, and von Neumann did ground-breaking work in all of them. One Hungarian physicist, asked to explain why his country had produced so many geniuses, replied that the only “Hungarian phenomenon” was von Neumann.

Von Neumann’s variety irritated his contemporaries

His astonishing range may be part of the reason that his career as a productive scientist lasted so long. He spent his life throwing out ideas in all manner of fields. As he was joining the Manhattan Project — his contribution was to design the arrangement of explosives that would most effectively compress the bomb’s plutonium core — he was also finishing a book on game theory.

He would turn out to have influenced both sides of the nuclear war game. In the 1940s he worked with the physicist Klaus Fuchs to develop a thermonuclear bomb. Unfortunately, Fuchs was also a Soviet spy and reported this to his masters, spurring them to develop their own version, something that ultimately made a first-strike war too risky for the US.

Von Neumann’s variety irritated his contemporaries. At the end of his life, his protégé Benoit Mandelbrot said mathematicians “were despising him for no longer being a mathematician”, while physicists “were despising him for never having been a real physicist”. Most of all, everyone at Princeton resented his having brought to the institution “this collection of low-class individuals called ‘programmers’”.

As a sometime member of that despised group, I feel able to say that we would cheerfully claim him. It was he, Bhattacharya argues, who saw that Alan Turing’s theoretical universal computing machine — which the Englishman came up with to prove a mathematical point — could actually be built. Almost every modern computer uses what became known as the “von Neumann architecture”. If you feel yours is going too slowly, you may be able to blame the design’s main flaw, the limits on moving data to and from memory, known as the “von Neumann bottleneck”.

But again, this was just one part of the man’s monumental output. As you play chess against your handheld von Neumann device, there’s a reasonable chance that it’s using the “minimax” strategy he first described to win what he first identified as a “zero-sum game”.

At the end of the book, the reader is left facing the same problem that has faced everyone trying to describe its subject succinctly

To attempt to put his subject into context, Bhattacharya takes wide, fascinating digressions. The chapter on the RAND Corporation is a particular highlight, explaining the history and impact of a group that, with its ideas about mutually-assured destruction and a “winnable” nuclear exchange was so influential in the early Cold War. And he goes far past von Neumann’s 1957 death to explore how his ideas about self-replicating machines have or might yet come to pass.

In this area his impact has so far been more in fiction than fact. It was von Neumann who first described as the “singularity” the moment when technology might begin to grow outside of human control, destroying our civilisation. One close reader of his writing on the subject was Philip K Dick, whose books would inspire films including Blade Runner, but the idea would appear elsewhere, from Battlestar Galactica to Terminator.

At the end of the book, the reader is left facing the same problem that has faced everyone trying to describe its subject succinctly. Who was John von Neumann? If in his life colleagues were reluctant to claim him, his legacy is now seen from science fiction to computing to economics.

As death approached, von Neumann attempted to address his fears about death by embracing Catholicism — “a very rough religion to live in”, he’d told his daughter, but “the only one to die in”. It surprised friends from his days working on the bomb. “If Johnny is where he thought he was going,” one joked at his funeral, “there must be some very interesting conversations going on.”