“Suffer” is the family motto of the Haldane clan, and, along with a line from Aeschylus — “We suffer into knowledge” — it is the epigraph of Samanth Subramanian’s “A Dominant Character,” a fascinating biography of the British biologist J. B. S. Haldane. In England, Haldane was a scientific celebrity as famous as Einstein. One of his contemporaries called him “the last man who might know all there was to be known.” But he lived a life of epic suffering, much of it self-inflicted, and the political dimension of his story speaks to the pain that we are living through now. The self-infliction began early. His father, John Scott Haldane, an eminent physiologist, often used himself as a human guinea pig in his research, and his son, known as Jack, served as assistant guinea pig. When Jack was 13, in 1906, his father sent him over the side of a torpedo gunboat in an ill-fitting diving suit weighing 155 pounds and then raised and lowered him by stages to test the best method to avoid “the bends.” On another ship, John killed plague rats with experimental doses of sulfur dioxide, while Jack dashed down into the hold to help collect the dead ones. It was Jack’s father who invented the idea of taking canaries into mines. Along with the canary, there was young Jack. Deep in an old coal pit in Staffordshire, he recited “Friends, Romans, countrymen…” for his father until the methane in the air made the boy collapse. Image Haldane seems to have enjoyed it: the science, the risk, the suffering for a cause. Brilliant and intellectually omnivorous, he studied the classics and mathematics at Oxford while doing genetics experiments on the side. When the outbreak of World War I interrupted his schooling, he worked on his first genetics paper in the trenches. He made himself an expert in hand-thrown bombs and discovered that he loved killing. One general called him “the bravest and dirtiest soldier in my army.” Wartime was one of the best times in Haldane’s life; forever after, he would dream sweet dreams of the front lines. Thanks for reading The Times. Subscribe to The Times When the Great War was over, he threw himself just as fiercely into research. Darwin’s theory of evolution by natural selection had been weakened by his ignorance of the laws of inheritance — he never read Mendel’s papers on the subject. And Mendel, breeding peas and bees in his monastery garden, seems to have missed the full significance of his own studies for Darwinism. Haldane helped bring their work together in what is known as the “modern synthesis.” Thanks in good part to the insights of Haldane and a few other gifted, mathematically-minded researchers, evolutionary biology became a powerful science that embraces a vast range of temporal and physical scales, from the passage of geological ages to the collision of a single sperm and egg, from the biosphere to the gene. In Mendelian genetics, a “dominant character” is a trait (such as smoothness in peas) that invariably prevails over another (in this case, wrinkledness) when genes for both are passed on to an offspring. Haldane was dominant, never recessive. He lived “a boisterous life,” Subramanian writes, “stocked with enough danger and drama for a dozen ordinary humans.” A reporter once described him as “a large woolly rhinoceros of uncertain temper.” He made an arresting figure at the podium — as Subramanian puts it: “a king-size man in rumpled clothes, his mustache so thick and his head so large and bare that it was as if a bird had built a nest at the base of a boulder.” As his father’s assistant, he’d risked his neck and his lungs to improve the working conditions of divers, sailors and miners. As a soldier, he’d relished not only the savagery of combat but also the comradeship of the trenches. He wanted science to help everyone, not just his own privileged, patrician class. He thought the Soviet experiment promised to do that, and he became a communist — eventually chairman of the editorial board of The Daily Worker. Editors’ Picks The 10 Best Books Through Time Will These Two Classic New York Eateries Survive the Pandemic? Subramanian, a journalist and regular contributor to The Guardian, is a strong writer, and he recounts Haldane’s communist adventures with brio: the hoarse, roaring speeches in Trafalgar Square; the admiring trip to Stalin’s Soviet Union; the tour of the front lines of the Spanish Civil War, where Haldane kicked around a bit with Hemingway and Martha Gellhorn. (He almost got them all blown up.) In London during the Blitz, Haldane designed a giant, inexpensive underground bomb shelter that he argued could save thousands of lives. These “Haldane Shelters” were never built. To Haldane that was another crime of capitalist society, and in this telling, at least, he had a case. British intelligence kept him under surveillance for more than 20 years on the suspicion — probably unfounded — that he was a Soviet spy. (In a way, as Subramanian says, MI5 was Haldane’s first biographer.) Image A national conference for British-Soviet unity held in London in 1946. J.B.S. Haldane, a committed communist, championed the Soviet Union long after Stalin began slaughtering his people. A national conference for British-Soviet unity held in London in 1946. J.B.S. Haldane, a committed communist, championed the Soviet Union long after Stalin began slaughtering his people.Credit...The New York Times “I am a man of violence by temperament and training,” Haldane once declared. He liked to claim that he was descended from Pedro the Cruel, the king of Castile and Léon. With his passion, his iconoclasm and his willingness to shock, his celebrity grew and grew. People liked his sensational stories of self-experimentation. (He continued his father’s physiological research; a fit of convulsions in one self-designed chamber of horrors broke his back.) They loved reading about his scandalous first marriage to Charlotte Burghes, a journalist, which made the British tabloids and almost got him kicked out of Cambridge, where he had taken a position as a reader in biochemistry. She was married when they met; her divorce was ugly; their own union was unconventionally loose. (His next marriage was to Helen Spurway, a biologist who was 22 years younger than he was.) In lectures — which drew large crowds — and in pubs, Haldane tossed off important and futuristic ideas like firecrackers. He wrote a revolutionary paper that helped transform the way biologists think about the origin of life. His vision of what would become known as test-tube babies helped inspire Aldous Huxley’s “Brave New World.” Haldane was a terrific writer in his own right. His political essays were “like razor blades in print,” Subramanian says. His science essays were superb. In one of his best, “On Being the Right Size,” Haldane writes, “You can drop a mouse down a thousand-yard mine shaft; and, on arriving at the bottom, it gets a slight shock and walks away, provided that the ground is fairly soft. A rat is killed, a man is broken, a horse splashes.” What a sentence. That last word shocks you every time — and you can hear in it more than a hint of his genetic inheritance from Pedro the Cruel. At his best, Haldane was a heroic example of the scientist as activist, humanist and idealist. “He felt, as we now feel afresh in our century,” Subramanian writes, “that nations were held rapt by the wealthy, that they were warmongering and venal, that they placed the narrow interests of the powerful above the well-being of the powerless.” Many of his views on class and race have aged well. But he picked petty fights wherever he went; and he championed the Soviet Union long after Stalin began slaughtering his people and murdering his geneticists. Haldane put himself through disgraceful intellectual contortions to defend Stalinist pseudoscience. Marx thought a single theory would someday cover everything from the laws of physics to the laws of human progress: “There will be one science.” It was Haldane’s great accomplishment to help make biology one science, with the modern synthesis. To do more, to explain the tragic messiness of history — that kind of synthesis continues to elude us. It’s hard enough to sum up the good and the bad in one human being. “A Dominant Character” is the best Haldane biography yet. With science so politicized in this country and abroad, the book could be an allegory for every scientist who wants to take a stand. “In the past few years,” Subramanian writes, “as we’ve witnessed deliberate assaults on fact and truth and as we’ve realized the failures of the calm weight of scientific evidence to influence government policy, the need for scientists to find their voice has grown even more urgent.” Haldane’s political principles were “unbending and forthright,” as Subramanian says, and his science illuminated all of life. In both these ways, for all his failings, he was “deeply attractive during a time of shifting, murky moralities.”