There is little dissent that Keynes, judged by his economic scholarship, had a transformative impact on his profession and on the world through the policies that adopted his ideas. Keynes’s magnum opus The General Theory of Employment, Interest and Money (1936) continues to influence theorists and policymakers as a foundational text much like Adam Smith’s The Wealth of Nations (1776) or Karl Marx’s Das Kapital (1867). By shifting the emphasis away from free-market orthodoxy towards social welfare, from scarcity toward redistribution, Keynes provided intellectual ammunition to socially oriented governments against classical and neoclassical liberal adherents. In advocating vigorous public action to counter market failures, he sought to mitigate the damage resulting from uncertainty and human irrationality. Similarly, since financial markets could not accurately price in uncertainty given ever-changing world conditions, it was necessary to regulate them. In times of depression, Keynes argued, governments had a moral obligation to increase spending and decrease suffering. Carter’s contribution is to humanise Keynes the theorist by illustrating his personal contradictions, such as his occasional anti-Semitism, his love of worldly privilege, and his naïveté concerning predictable realpolitik machinations.

George Bernard Shaw and John Maynard Keynes, 1935 (Alamy)

Numerous anecdotes demonstrate the complexity and evolution of Keynes as a thinker and as an individual. Starting from the position of an unabashed free trader, Keynes renounced that to embrace tariffs as a response to Britain’s rigid (and doomed) belief in a gold standard, readopted after World War I. Keynes’s early scepticism about econometric analysis that reduces the economy into variables gave way to an approach anticipating an era of ‘joy through statistics’. In a letter to his fellow Bloomsbury intimate and lover Duncan Grant, Keynes reveals his disgust at working for a government he despised even as he revelled in his role as a fêted adviser and public intellectual. His love of art and beauty motivated him to authorise the purchase of French Post-Impressionist art with public funds, despite a financial crisis in Great Britain and the escalating costs of fighting World War I. Notwithstanding inherent conflicts of interest that would be considered illegal today, Keynes invested in stocks and commodities whose values were affected by his position as a government official. Besides rubbing shoulders with the likes of British prime ministers Lloyd George and Winston Churchill, Keynes also cultivated relationships with the clever and the famous throughout his life: Albert Einstein, Felix Frankfurter, Joan Robinson, Ludwig Wittgenstein, and Virginia Woolf, with whom he spent his Christmases until her death in 1941.

Some of Keynes’s relationships had surprising consequences, such as how his tract The Economic Consequences of the Peace (1919) was the inspiration for T.S. Eliot’s masterpiece The Waste Land (1922). (Keynes had also offered the poet a job.) More consequential would be how many of the policies that Keynes had proposed would be eagerly adopted in the United States, specifically under the administration of President Franklin Delano Roosevelt. Through regular correspondence with Roosevelt, Keynes would flatter and cajole the president to push ahead with government programs like the New Deal to help the economy recover from the Great Depression. His acolytes like Robinson, John Kenneth Galbraith, and Paul Samuelson continued this process in university classrooms and government agencies on both sides of the Atlantic, ensuring that his intellectual legacy remained visible and relevant to the economic problems of the twentieth century.

Carter’s enthusiasm for Keynes is evident throughout his book, for better and worse. While Keynes has clearly made an outsized impact on policy and his profession, which even has a major school of thought named after him, the relentless praise Carter heaps on Keynes comes across as uncritical and hyperbolic. Was Keynes really the most important or powerful intellectual of the twentieth century? Is it true that the failures in policy between World War I and the onset of the Great Depression were due simply to the inability of European policymakers to recognise Keynes’s brilliance? Carter gives Keynes credit for reshaping US economic policy during the 1930s despite public works programs like the National Recovery Administration having been initiated before the publication of The General Theory or broader awareness of Keynes’s theories.

Unusual for a biography, the book does not end with Keynes’s death but continues for nearly two hundred pages more as a coda that elaborates on Keynesian policies in the United States. The unwieldy substitution of Galbraith as protagonist for Keynes makes more sense if the book’s primary objective were an analysis of Keynesian theories in comparative perspective, but it makes for a jarring contrast to sections describing Keynes’s sexual proclivities and infidelity to his wife or loosely sketched summaries of economic theories. The loss of coherency is compounded by the assertive authorial voice Carter inserts in his narrative. Do readers care if Carter, as opposed to Keynes, has satisfying answers to why democracies make poor economic choices or if he thinks societies organised around profit incentives will have dirty parks? Are snappy quips or rhetorical cliffhangers necessary to end chapters, as if this biography were a hard-boiled whodunit or serialised Bildungsroman? These stylistic tics undermine Carter’s professed aim to show the transformative implications of Keynesian ideology, and instead trivialise a man’s life and work.

The paradox and fascination of Keynes is that he was both a man of his time and one who shaped it. While his legacy is ill served by Carter’s uneven biography, Keynes’s contributions remain as relevant today as they were a century past.