🇬🇧Bertrand
Russell

Bertrand Russell discovered Euclidean geometry at the age of eleven, when his older brother Frank sat him down with the first book of Euclid and began working through the axioms and propositions. He later described the experience as one of the most significant of his life — not because the mathematics was difficult, but because it was the first time he had encountered the idea that one could begin with premises that seemed obviously true and reason, step by step, to conclusions that were not at all obvious. He was a lonely child, orphaned at three and raised by a strict, Calvinist grandmother in a large house in Surrey. The discovery of mathematics was a discovery of certainty, and he clung to it. He spent much of the next decade trying to verify that Euclid's axioms were indeed as certain as they seemed. By the time he finished Principia Mathematica with Alfred North Whitehead, thirty-five years later, he had definitively established that they were not — and had in the process created modern mathematical logic.

Born on May 18, 1872, in Trellech, Monmouthshire, Wales, Bertrand Arthur William Russell was the grandson of Lord John Russell, who had twice served as British Prime Minister, and inherited the earldom as the third Earl Russell upon his brother's death. He entered Trinity College, Cambridge in 1890 and read mathematics, placing seventh wrangler — a respectable but not outstanding position — in the Mathematical Tripos of 1893. He then turned to philosophy. His Fellowship dissertation, published as An Essay on the Foundations of Geometry (1897), was his first serious work. He followed it rapidly with A Critical Exposition of the Philosophy of Leibniz (1900), in which he argued that Leibniz's metaphysics was systematically flawed at its foundations — a claim that remains influential in the history of philosophy.

The Principles of Mathematics (1903) laid out Russell's central project: to reduce all of mathematics to pure logic, demonstrating that mathematical truth was logical truth and required no separate domain of abstract objects. But while writing this book, Russell discovered what became known as Russell's Paradox — a fundamental contradiction at the heart of naive set theory. Consider the set of all sets that do not contain themselves as a member. Does it contain itself? If it does, then it doesn't; if it doesn't, then it does. The paradox showed that the logical foundations of mathematics were not as secure as anyone had assumed, and required either a completely new logical system or substantial revision of the concept of set. Russell spent the next decade, working with Whitehead, developing the theory of types to resolve the paradox — resulting in the three-volume Principia Mathematica (1910–1913), one of the most technically demanding works in the history of human thought.

But Russell was never only a logician. He was also one of the most gifted prose writers in the English language, and he deployed that gift across an enormous range of subjects — the history of western philosophy, the analysis of mind, the nature of happiness, the education of children, the ethics of war, the dangers of nationalism, the meaning of marriage. His History of Western Philosophy (1945) — written partly to raise money and partly out of genuine synthetic ambition — became an international bestseller and remains in print, despite being, in the view of professional philosophers, frequently inaccurate and almost always brilliant. The Nobel Committee, awarding him the Prize in Literature in 1950, cited his "varied and significant writings in which he champions humanitarian ideals and freedom of thought." They were describing a man who had been imprisoned for six months during World War I for his pacifist writings, dismissed from Trinity College Cambridge for the same reason, and barred from teaching at City College New York in 1940 because a judge ruled his books immoral.

In 1955, Russell and Albert Einstein co-authored the Russell-Einstein Manifesto, calling on all nations to seek peaceful resolution of conflict and warning of the catastrophic consequences of nuclear war. Russell was ninety-two when he organised the mass sit-down protest in Trafalgar Square against nuclear weapons in 1962. He was ninety-four when he publicly condemned the American military presence in Vietnam. He continued writing, speaking, and campaigning until his death on February 2, 1970, at the age of ninety-seven. He published his last book two years before he died. The range and volume of his intellectual output across a career of nearly eighty years is without parallel in the twentieth century.

Russell's personal life was as eventful as his intellectual one. He was married four times, had numerous affairs, and held views on marriage and sexuality that were, by the standards of his era, scandalous. He was a consistent advocate for what he called "companionate marriage" and for the sexual education of children. He founded a progressive school, Beacon Hill, with his second wife Dora Black, which attempted to put his educational philosophy into practice. He won custody battles, lost academic positions, survived two World Wars, and lived to see the movement he had helped inspire — the Campaign for Nuclear Disarmament — become a global force. When he died, a generation of young people across the world felt, as one obituarist put it, that their grandfather had died.