Like Odysseus, Keynes was a successful, not a tragic, hero. He heard the beautiful singing of the Sirens, but took precautions against being shipwrec… - Robert Skidelsky

Keynes was one of those rare persons who can both think and act at the highest level. His life falls into cycles or phases, in which the emphasis shifts from one to the other. These shifts were related to what was happening in the world. At some times, particularly during the two world wars, there was a greater demand for Keynes's practical genius, and a greater satisfaction to be had from exercising it. But the cycles can also be seen in terms of action and reaction. Periods of great intellectual effort demand their release in practical activity, while practical activity prompts, sooner or later, a yearning for the cloister. Before 1914, Keynes's desire for the cloister was uppermost, partly because he was at this period most under the immediate influence of Moore's philosophy, partly because the nature of his sexual relations fitted private life better than public life ― a point of considerable importance even today, but more so then, when homosexual acts were illegal, and the danger of blackmail much greater.

The General Theory of Employment, Interest and Money is a work of enduring fascination. It is simple and subtle, obscure and profound. It offered a systematic way of thinking not just about the behaviour of contemporary economies, but about the pitfalls in the quest for greater wealth at all times. It combined a vision of the future with a rigorous demonstration of the possibility of underemployment equilibrium. Although young economists of speculative bent were drawn to it as a storehouse of suggestive ideas, it was its practical usefulness which chiefly attracted them in a world poised between decaying democracy and rampaging dictatorship.
At its core is a 'theory of output and employment as a whole', to distinguish it from the orthodox theory of what causes 'the rewards and distribution between different uses of a given quantity of resources' to be what they are. Keynes was the first economist to visualise the economy as an aggregate quantity of output resulting from an aggregate stream of expenditure. This new way of seeing the architecture of an economy is the General Theory's most enduring legacy.

Having said this, it is easy to see that he might have been deluding himself. He envisaged a modern capitalist economy governed by a Platonic ideal, and gentlemanly codes of behaviour. But once the capitalist genie is let out of the bottle it cannot be pressed into the service of a pre-modern ethics of the good life and pre-modern codes of behaviour. The good life in the classical sense presupposes that human desire has some ultimate end, or telos, whereas modern economic theory and life presuppose that it is insatiable. As regards behaviour, he took for granted a class-based system of values which economic progress was undermining. These were contradictions which Keynes never fully faced.