Maynard Keynes was a phenomenon. The most renowned economist of his generation, he also twice acted as a government official - as the chancellor's deputy at the Paris peace conference and playing the leading part at the Bretton Woods conference. A year later, he was responsible for negotiations that led to Britain securing the postwar American loan. A non-conformist by inheritance and nature, he delighted in challenging traditional orthodoxies, always bringing a sharp pen and a tart tongue to the task.
When he died in 1946, great care was taken by family and friends to protect the secret of his early life - as a key member of the Bloomsbury Group, he had been a rampant and reckless homosexual. This did not, however, inhibit The Times from suggesting in the 1970s that his disregard of economic rules flowed from the undiscipline of his personal life.
This was all, of course, great nonsense. Everything else apart - as this third and final volume of Lord Skidelsky's comprehensive biography demonstrates - Keynes himself became a classic pillar of the establishment. Not content with his eminence as an economist, he played an active and influential part in the arts. He died a hereditary baron, a fellow of Eton, a trustee of the National Gallery and a director of the Bank of England.
Robert Skidelsky - now himself a Conservative peer in the House of Lords - deals with these latter years of grandeur with assurance and aplomb.
If this concluding volume lacks the bite and irreverence that characterised the earlier parts of Keynes' career, it is because by the late '30s Keynes had ceased to be regarded as a heretic. Indeed, for some of the period covered in this volume he was near to being, the author writes, 'the de facto chancellor of the Exchequer' - someone with immense personal authority.
But that did not stop him from always appearing as 'a solitary mountain towering over the foothills'.
He owed his status principally to the sheer creative power of his brain.
But it was not merely a question of intellect. 'The trouble with Maynard,' his wife once said, 'is that he has abnormal will power. I suppose there is nothing to be done about it.'
This book demonstrates vividly that there wasn't. At the start of the volume Keynes is already in poor health. But he did not allow that to affect his essentially competitive, combative nature. Lying in bed after reading an article critical of him by a fellow Cambridge economist, he announced without any sense of incongruity: 'It seems to me like the work of a sick man.'
Writing from the standpoint of the Social Market Foundation, Skidelsky - before his conversion to Conservatism, a former acolyte of David Owen within the SDP - possesses reservations about some of his subject's economic theories. He is particularly sceptical of Keynes' belief that unemployment was a soluble problem and that full employment did not always have within it the potential to cause a wages explosion - quoting with wry satisfaction a remark made to him by a Keynes disciple in the '70s: 'We never thought that the leaders of the trade unions would behave so stupidly.'
But if Keynesianism took a battering in the '70s, only a free-market ideologue would deny it has since made something of a comeback. What showpiece, after all, can Milton Friedman offer for his rival theory of monetarism - Pinochet's Chile? Skidelsky manages to be optimistic about the new international outlets he believes are now open to Keynes' doctrines.
This is a thoroughly fair-minded book, diligently researched and elegantly written. It crowns the edifice of one of the outstanding biographical enterprises of our time. Unlike Roy Harrod's Life of Keynes, it hides little or nothing, enabling us to understand far more about one of the giants of the 20th century.