David Hume, Adam Smith, John Stuart Mill, and Henry Sidgwick, together with a series of lesser-known names, form a distinguished line of British philosopher-economists spanning much of the 18th and 19th centuries. Modern economics is different, for the emphasis is on economics as a science, centered on the quantitative methods that are now considered a prerequisite for entry into the field. Contemporary economics possesses a set of techniques that have enabled it to become the hardest of the social sciences, closer to physics than to philosophy. As Hayek pointed out in his critique of scientism, the claim to be scientific has become an important rhetorical device [Hayek, 1952]. There are exceptions, such as Amartya Sen, but although they may be respected by the profession (especially if they win the Nobel Memorial Prize), they are the examples that prove the rule.
Perhaps the last great economist in the tradition of philosopher--economists was John Maynard Keynes. There is a deep irony in this, for modern economics is unimaginable without Keynes; macroeconomics and econometrics both took their modern forms in the wake of the Keynesian revolution. Keynesian economics came to be identified with economic modeling of a type that was rare before the Second World War. This means that when economists look back at Keynes, they see a forerunner of their own work, doing macroeconomic science, albeit in a somewhat casual and unsatisfactory way. Thus Milton Friedman can speak of Keynes as his kind of economic scientist.
As extensive documentary evidence has come to light with the publication of Keynes's Collected Writings, and careful examination of the archival record of his early philosophical work [Carabelli, 1988; O'Donnell, 1989; Bateman, 1988, 1996], and this work has been analyzed by biographers and other scholars, it has become clear that this perspective of Keynes as the precursor of all that is modern in economics leaves out much. For Roy Harrod, his official biographer, Keynes's Bloomsbury connections were seen very much as part of his early life, which was of minimal importance to his mature economics, represented in The General Theory of Employment Interest and Money [Keynes, 1936] or even his economic writings of the 1920s and early 1930s. This has been challenged on two fronts. Much of the "Keynes and philosophy" literature [Davis, 1994; O'Donnell, 1989; Carabelli, 1988; Bateman, 1987, 1988, 1990, 1996; Fitzgibbons, 1988; Bateman and Davis, 1991; Gillies and Ietto-Gillies, 1991; Coates, 1996] was based on exploring the connections between his youthful work on the theory of probability, with its grounding in the philosophy of induction and its origins in an unresolved ethical questions in G.E. Moore's philosophy, and his economics. In that they remained controversial, the precise nature of those links was not altogether clear. The other challenge was Robert Skidelsky's [1983, 1992, 2002] biography, which painted a picture of a "Bloomsbury" Keynes, whose personal values were formed by his involvement with his philosophical and artistic friends.
Our aim is to argue, on the basis of such arguments and still more recent work, that there is a strong case for considering Keynes, not as an economic scientist in the modern sense of the term, but as a philosopher-economist comparable with Hume, Smith, Mill and Sidgwick. He may have written only one major philosophical work, his Treatise on Probability [Keynes, 1973a], and it may indeed be the case that he decided, unlike his distinguished predecessors, not to make a career in philosophy; but for all that, his life's work (or his work in economics) makes more sense in the context of his philosophy than independently of it. Paradoxically, one of the main differences between Keynes and the other British philosopher-economists mentioned is not that he was a scientist, but that he was, or sought to be, an artist-the only major economist who lived among a group of artists and who was a central figure in a powerful artistic and literary movement [Skidelsky, 1983, 1992, 2002; Goodwin, 2006].
The argument starts by exploring how Keynes saw his own career, ex ante and (almost) ex post. This is a story of someone who wished to be an artist, motivated by ideas he had obtained from his Cambridge mentors in philosophy and his Bloomsbury friends. The essay then adumbrates
Keynes's explicit philosophical involvement, covering not simply his probability (though that is clearly an important part of it) but also his writing on ethics. It then turns to his artistic involvements. Finally, we turn to his economics, viewed in the light of these ideas. A key figure here is Alfred Marshall. Marshall was not just Keynes's teacher, and the dominant figure behind the orthodoxy against which he later chose to rebel, but he was, with his friend and one-time mentor Sidgwick, central to the movement of economics away from philosophy. Notwithstanding that, the strong similarities between Marshall's work and Keynes's help show the gap between Keynes's economics and much of the Keynesianism that has followed him. Conclusions are then drawn.
Keynes on Keynes
On 21 June 1921, Maynard Keynes delivered the presidential address to the annual reunion of the Apostles an exclusive society of Cambridge University students and alumni that involved Cambridge's leading philosophers, including Henry Sidgwick, John McTaggart, G. E. Moore, Bertrand Russell, Alfred North Whitehead and Frank Ramsey [Skidelsky, 1992, Prologue]. What had united the Apostles of Keynes's own generation were their commitments, learned from G. E. Moore, to absolute truth and to the search for friendship and beauty. The ideal career for Keynes's cohort of Apostles would have been to become an artist, creating beauty and living in a community of other artists with whom one had close bonds of friendship. But what should one do if one could not commit oneself to a career making art? What …