"Keynes was unmistakably a man formed by the previous century. In the first place, and like so many of the best economists of the earlier generations, from Adam Smith to John Stuart Mill, Keynes was primarily a philosopher who happened to deal in economic data. He might just as well have been a philosopher had the circumstances positioned him differently; indeed, in his Cambridge years, he wrote some properly philosophical papers, albeit with a mathematical bent. As an economist, Keynes always saw himself responding to the nineteenth-century tradition in economic reasoning. Alfred Marshall and the economists who followed J. S. Mill had assumed that the default condition of markets, and therefore of the capitalist economy at large, was stability. Thus instabilities—whether economic depression, or distorted markets, or government interference—were to be expected as part of the natural order of economic and political life; but they did not need to be theorized as part of the necessary nature of economic activity itself. Even before the First World War, Keynes was beginning to write against this assumption; after the war, he did little else. Over time he came to the position that the default condition of a capitalist economy could not be understood in the absence of instability and the inevitably accompanying inefficiencies. The classical economic assumption, that equilibrium and rational outcomes were the norm, instability and unpredictability the exception, were now reversed. Moreover, in Keynes’s emerging theory, whatever it was that caused instability could not be addressed from within a theory which was unable to take that instability into account. The basic innovation here is comparable to the Gödelian paradox: as we might put it today, you cannot expect systems to resolve themselves without intervention. Thus, not only do markets not self-regulate according to a hypothetically invisible hand, they actually accumulate self-destructive distortions over time. Keynes’s point is an elegantly symmetrical bookend to Adam Smith's claim in The Theory of Moral Sentiments. Smith argued that capitalism does not in itself generate the values that make its success possible; it inherits them from the pre-capitalist or non-capitalist world, or else borrows them (so to speak) from the language of religion or ethics. Values such as trust, faith, belief in the reliability of contracts, assumptions that the future will keep faith with past commitments and so on have nothing to do with the logic of markets per se, but they are necessary for their functioning. To this Keynes added the argument that capitalism does not generate the social conditions necessary for its own sustenance."
January 1, 1970
https://en.wikiquote.org/wiki/John_Maynard_Keynes