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, … - Robert Skidelsky

A work of genius is a complex object and there is light to be shed about what went into the making of it. Even in the case of scientific and mathematical achievement we can say a great deal about the existing state of knowledge, the problems it failed to address, why those problems were or had become interesting, the particular capacities which the solver brought to their solution. At the other extreme is a work of art which seems to have much more immediate roots in the personal life of the artist or writer. In between is the area in which Keynes worked, which was partly scientific, partly artistic. This gives a wide justification for a biographical approach. As I put it in the introduction to my first volume: 'If underlying Keynesian theory was Keynes's vision of his age, knowledge of his state of mind and the circumstances which formed it is essential, not only in order to understand how he came to see the world as he did, but also in order to pass judgement on the theory itself.'

Like Odysseus, Keynes was a successful, not a tragic, hero. He heard the beautiful singing of the Sirens, but took precautions against being shipwrecked, keeping to the course for which his talents and the state of the world predestined him. Artfully, he strove for the best of all worlds, in his life and his work, and miraculously, came close to achieving it.

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.