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Ian Hacking, eminent philosopher of science and much else, dies at 87

Dr. Hacking taught at the University of Toronto, among other institutions.VIA JANE FRANCES HACKING/NYT

Ian Hacking, a Canadian philosopher widely hailed as a giant of modern thought for game-changing contributions to the philosophies of science, probability, and mathematics, as well as his widely circulated insights on issues such as race and mental health, died May 10 at a retirement home in Toronto. He was 87.

His daughter Jane Hacking said the cause was heart failure.

In an academic career that included more than two decades as a professor in the philosophy department of the University of Toronto, following appointments at the University of Cambridge and Stanford University, Dr. Hacking offered an intellectual scope that seemed to know no bounds. Because of his ability to span multiple academic fields, he was often described as a bridge-builder.


“Ian Hacking was a one-person interdisciplinary department all by himself,” Cheryl Misak, a philosophy professor at the University of Toronto, said in a phone interview. “Anthropologists, sociologists, historians, and psychologists, as well as those working on probability theory and physics, took him to have important insights for their disciplines.”

A lively and provocative writer if often a highly technical one, Dr. Hacking wrote several landmark works on the philosophy and history of probability, including “The Taming of Chance” (1990), which was named one of the best 100 nonfiction books of the 20th century by the Modern Library.

His many honors included the Holberg Prize, an award recognizing academic scholarship in the humanities, social sciences, law, and theology, which he was awarded in 2009. In 2000, he became the first Anglophone to win a permanent position at the Collège de France, where he held the chair in the philosophy and history of scientific concepts until he retired in 2006.

His work in the philosophy of science was groundbreaking: He departed from the preoccupation with questions that had long concerned philosophers. Arguing that science was just as much about intervention as it was about representation, he helped bring experimentation to center stage.


Regarding one such question — whether unseen phenomena such as quarks and electrons were real or merely the theoretical constructs of physicists — he argued for reality in the case of phenomena that figured in experiments, citing as an example an experiment at Stanford that involved spraying electrons and positrons into a ball of niobium to detect electric charges. “So far as I am concerned,” he wrote, “if you can spray them, they’re real.”

His book “The Emergence of Probability” (1975), which is said to have inspired hundreds of books by other scholars, examined how concepts of statistical probability have evolved over time, shaping the way we understand not just arcane fields like quantum physics but also everyday life.

“I was trying to understand what happened a few hundred years ago that made it possible for our world to be dominated by probabilities,” he said in a 2012 interview with the journal Public Culture. “We now live in a universe of chance, and everything we do — health, sports, sex, molecules, the climate — takes place within a discourse of probabilities.”

As the author of 13 books and hundreds of articles, including many in The New York Review of Books and its London counterpart, he established himself as a formidable public intellectual.

Whatever the subject, whatever the audience, one idea that pervades all his work is that “science is a human enterprise,” Ragnar Fjelland and Roger Strand of the University of Bergen in Norway wrote when Dr. Hacking won the Holberg Prize. “It is always created in a historical situation, and to understand why present science is as it is, it is not sufficient to know that it is ‘true,’ or confirmed. We have to know the historical context of its emergence.”


Influenced by French philosopher and historian Michel Foucault, Dr. Hacking often argued that as the human sciences have evolved, they have created categories of people, and that people have subsequently defined themselves as falling into those categories. Thus does human reality become socially constructed.

“I have long been interested in classifications of people, in how they affect the people classified, and how the effects on the people in turn change the classifications,” he wrote in “Making Up People,” a 2006 article in The London Review of Books.

“I call this the ‘looping effect,’ ” he added. “Sometimes, our sciences create kinds of people that in a certain sense did not exist before.”

In “Why Race Still Matters,” a 2005 article in the journal Daedalus, he explored how anthropologists developed racial categories by extrapolating from superficial physical characteristics, with lasting effects — including racial oppression. “Classification and judgment are seldom separable,” he wrote. “Racial classification is evaluation.”

Similarly, he once wrote, in the field of mental health the word “normal” “uses a power as old as Aristotle to bridge the fact/value distinction, whispering in your ear that what is normal is also right.


In his influential writings about autism, Dr. Hacking charted the evolution of the diagnosis and its profound effects on those diagnosed, which in turn broadened the definition to include a greater number of people.

Encouraging children with autism to think of themselves that way “can separate the child from ‘normalcy’ in a way that is not appropriate,” he told Public Culture. “By all means encourage the oddities. By no means criticize the oddities.”

His emphasis on historical context also illuminated what he called transient mental illnesses, which appear to be so confined to their time that they can vanish when times change.

For instance, he wrote in his book “Mad Travelers” (1998), “hysterical fatigue” was a short-lived epidemic of compulsive wandering that emerged in Europe in the 1880s, largely among middle-class men who had become transfixed by stories of exotic locales and the lure of travel.

His book “Rewriting the Soul” (1995) examined the short-lived concern with the supposed epidemic known as multiple personality disorder, which arose around 1970 from “a few paradigm cases of strange behavior.”

“It was rather sensational,” he wrote, summarizing the phenomenon in the London Review article. “More and more unhappy people started manifesting these symptoms.” First, he added, “a person had two or three personalities. Within a decade the mean number was 17.”

“This fed back into the diagnoses, and became part of the standard set of symptoms,” he argued, creating a looping effect that expanded the number of those apparently afflicted — to the point that Dr. Hacking recalled visiting a “split bar” catering to them, which he compared to a gay bar, in 1991.


Within just a few years, however, multiple personality disorder was renamed dissociative identity disorder, a change that was “more than an act of diagnostic housecleaning,” he wrote. “Symptoms evolve, patients are no longer expected to come with a roster of altogether distinct personalities, and they don’t.”

Ian MacDougall Hacking was born Feb. 18, 1936, in Vancouver, the only child of Harold Hacking, who managed the cargo on freighter ships and was awarded the Order of the British Empire for his service in the Canadian army during World War II, and Margaret (MacDougall) Hacking, a milliner.

His intellectual tendencies were unmistakable from an early age. “When he was 3 or 4 years old, he would sit and read the dictionary,” Jane Hacking said. “His parents were completely baffled.”

He studied mathematics and physics at the University of British Columbia and, after graduation in 1956, went on to Trinity College Cambridge, where he earned a doctorate in 1962.

In addition to his daughter Jane, Dr. Hacking leaves another daughter, Rachel Gee; a son, Daniel; a stepson, Oliver Baker; and seven grandchildren. His wife, Judith Baker, died in 2014. His two previous marriages, to Laura Anne Leach and science philosopher Nancy Cartwright, ended in divorce.

Even in retirement, Dr. Hacking maintained his trademark sense of wonder.

In a 2009 interview with the Canadian newspaper The Globe and Mail, conducted in the garden of his Toronto home, he pointed to a wasp buzzing near a rose, which he said reminded him of the physics principle of nonlocality, the direct influence of one object on another distant object, which was the subject of a talk he had recently heard by physicist Nicolas Gisin.

He wondered aloud, the interviewer noted, if the whole universe was governed by nonlocality — if “everything in the universe is aware of everything else.”

“That’s what you should be writing about,” he said. “Not me. I’m a dilettante. My governing word is ‘curiosity.’ ”