A disturbing feature of 20th century intellectual history is that the dominant figures of the two main European philosophical traditions were decidedly conservative thinkers with strong authoritarian, even totalitarian, tendencies. I refer here, of course, to Martin Heidegger and Ludwig Wittgenstein. This point is only reinforced when an avowedly liberal thinker like Richard Rorty explains the significance of his own favorite figure, John Dewey, in terms of the views he shared with Wittgenstein and Heidegger. Rorty writes as if Karl Popper had never existed. However, as Hacohen rightly observes, had Rorty taken Popper's achievement more seriously, perhaps we would not be saddled with the postmodern predicament, whereby the failure of establish logical foundations for all thought opens the door to an endless proliferation of community-based epistemic standards. Indeed, a sign of our non-Popperian times is that the most natural way to interpret the idea of "social epistemology" is in terms of a consensus-seeking approach to inquiry, not, as Popper himself did, a set of mutually critical agents.
Popper's invisibility from most standard histories of modern philosophy is matched only by the ideological role he has played in the history of other disciplines, especially the social sciences. In the second half of the 20th century, Popper stood for the scientific method, objectivity, rationality, liberalism and individualism. Within academia he performed much the same function as his English mentor, Bertrand Russell, did outside it. Yet, even in death, Popper remains an awkward figure to place, both intellectually and politically. Nevertheless, Hacohen, a broadly educated intellectual historian, does an excellent job of disentangling the misunderstandings and myths surrounding Popper -- many promoted by the man himself -- typically by relying on evidence from archives on both sides of the Atlantic. However, in one important respect, the book's title is misleading, since the epilogue provides a 30-page sketch of how one would research Popper's four decades as presiding philosopher at the London School of Economics. While Hacohen claims he will not do the work himself, it seems to me that it could be easily turned over to someone else.
Hacohen's account implies some fascinating differences between Popper's philosophical personality and that of his world-historic rivals, Heidegger and Wittgenstein. To be sure, these were three megalomaniacs who thought all philosophy culminated in their thought. However, by accident or design, Heidegger and Wittgenstein were surrounded by rather impressionable students who claimed genius for their master, thereby sparing the master the indignity of doing so for himself. In contrast, it would seem that from his late teens, Popper was inclined to advertise his genius, which gave him a reputation for arrogance and petulance. Hacohen strikes just the right chord when dealing with this matter. Popper engaged numerous contemporaries in debate -- sometimes that seemed to be the only communication of which he was capable -- and then insisted on being recognized for some achievement resulting from it. This tendency especially annoyed the Vienna Circle, who first gave Popper some serious philosophical attention by publishing The Logic of Scientific Discovery in their book series. As the logician Tarski later put it, Popper always had the better argument but was never the nicer person. Moreover, as Hacohen shows repeatedly, while Popper learned from his interlocutors, he rarely acknowledged shifts in his position, let alone credited their sources. The potential for interpretive confusion is only compounded by Popper's otherwise admirable tendency to craft his prose as simply possible -- a strategy he picked up from Einstein's successful popularization of relativity theory.
Popper's style and practice have not stood him well in the historiography of philosophy. His dogmatic claims for his own genius were often read as philosophical dogmatism. Yet, most of his positive views were really negative ones in disguise: his rationalism was anti-inductivism, his liberalism anti-authoritarianism, his individualism anti-holism, and so forth. Consequently, Popper often presented his views as critical sketches that presuppose acquaintance with the details and history of what is being criticized. Failure to appreciate the profoundly dialectical character of Popper's thought has led to his portrayal as a relatively simple-minded thinker, such as the standard-issue "positivist" that came across to Adorno and Habermas in the Methodenstreit of the 1960s. Moreover, it did not help that so often Popper's adversaries were the self-declared keepers of the dialectical tradition!
This raises a more general problem in the interpretation of Popper's philosophical career: He seemed to be acutely aware of the reflexive dimension of thought without managing to escape its entanglements. An illuminating thread through Popper's philosophy would follow his interest in the ways the form of thought undermine, or otherwise transform, its content. Hacohen observes that Popper's youthful rejection of Marx and Freud was based on the dogmatic attitude that Marxists and Freudians had toward their masters' views, not the actual views themselves, with which Popper remained in considerable sympathy for much of his life. However, once this rejection was canonized as "the demarcation problem" in the philosophy of science, Popper's more globally normative, perhaps even ethical, concerns dropped out, and it became a technical matter that implied the rejection of the content of Marx's and Freud's theories. Conversely, when Hacohen reveals some correspondence between Popper and the man responsible for bringing him to the LSE, Friedrich von Hayek, it becomes clear that what Popper likes about capitalism is not its substantive fixation on free markets but the meta-level consequences of holding such a view, namely, that it makes one more responsive to the external world.
The deep point in all this is that certain views may be true (e.g. Marxism) yet because of the times and places in which we live, or the sort of person we are, believing these views as true may make ourselves and others worse people. Indeed, this explains Popper's aversion in later life to the quasi-religious appeals to unconditional commitment that Michael Polanyi and Thomas Kuhn associated with normal science. (This aspect of Popper's thought was developed in W.W. Bartley III, The Retreat to Commitment, 1962.) Unfortunately, as long as the history of philosophy continues to be written as a set of authoritative figures who attract acolytes and spawn canonical texts, Popper will not be given his due and the critical function of philosophy more generally will remain muted. However, to Hacohen's great credit, this will be much harder to do in the future.