The unconscious being unknowable, how can the psychoanalyst be certain that the memory he recovers with the help of hypnosis is real, or that his interpretations of the patient’s free associations are correct? How, in other words, can his theories be validated? The patient’s assent or dissent cannot be trusted in this regard since the theory predicts that he or she will “resist” the unveiling of the repressed, as illustrated by the “Dora” case. The scientific controversy that is the analytic cure cannot come to a conclusion since it takes the form of an analysis of resistance to analysis, more specifically, of an analysis of patients’ positive or negative transference onto the analyst. Even a confirmation by the patient of the analyst’s interpretations is not going to settle the matter since it might be yet another ruse of transference resistance. In the end, it is the analyst who decides whether the interpretation – and the theory behind it – is correct or not. Hence the crucial importance in psychoanalytic theory of Freud’s “self-analysis,” since it – and it only – guarantees that the founder initially gained unfettered access to the unconscious.

Chapter 12 criticizes Karl Poppers and Imre Lakatos’ views on theory appraisal, which have been particularly influential among writers on economic methodology, although their influence has waned. Popperian critics of economics are right to claim that economists seldom practice the falsificationism that many preach, but, in contrast to authors such as Mark Blaug (), I argue that the problem is with the preaching, not with the practice: falsificationism is not a feasible methodology. Although Lakatos provides more resources with which to defend economics than does Popper, his views are also inadequate and for a similar reason. Both Popper and Lakatos deny that there is ever reason to believe that scientific statements are close to the truth or likely to be true, and neither provides a viable construal of tendencies. In denying that such reasons to accept generalizations have a role in either engineering or in theoretical science, Popper and Lakatos are implicitly calling for a radical and destructive transformation of human practices.

Science works in trajectories. Whether we look from an individual, institutional, or international perspective, we focus our efforts on certain scientific pursuits and omit others. In an ideal world, of course, our efforts would be omnific in nature, pursuing every conceivable scientific trajectory to understand the world with near-perfect precision. At some point, however, we are forced to make a choice to pursue path A or path B – limited by resources, attention, and time. Frustratingly, knowing which path is likely to be most fruitful is often highly unpredictable. On the bright side, this also makes the discovery of new knowledge exciting.

A link is made between epistemology – that is to say, the philosophy of knowledge – and statistics. Hume's criticism of induction is covered, as is Popper's. Various philosophies of statistics are described.

This chapter defends Kuhn's appeal to the notion of "structure" in his analysis of science. I argue that Kuhn's SSR was not intended to be a contribution to the history of science.

Scientists and philosophers of science are most impressed by theories that make successful, novel predictions: that predict surprising facts in advance of their experimental or observational confirmation. There is a theory of cosmology that has repeatedly been successful in this privileged way, but it is not the standard, or 𝚲CDM, model. It is Mordehai Milgrom’s MOND theory (MOdified Newtonian Dynamics). Unlike the standard model, MOND does not postulate the existence of dark matter. Observations that are explained in the standard model by invoking dark matter are explained in MOND by postulating a change in the laws of gravity and motion.

Scientific epistemology begins from the idea that the truth of a universal statement, such as a scientific law, can never be conclusively proved. No matter how successful a hypothesis has been in the past, it can always turn out to make incorrect predictions when applied in a new situation. Karl Popper argued that the most important experimental results are those that falsify a theory, and he proposed falsifiability as a criterion for distinguishing science from pseudoscience. Popper argued in addition that scientists should respond to falsifications in a particular way: not by ad hoc adjustments of their theories, but in a way that expands the theory’s explanatory content. Popper argued that the success of a modified theory should be judged in terms of its success at making new predictions. Popper’s view of epistemology, which is shared by many scientists and philosophers of science, is called “critical rationalism.” An epistemology that judges success purely in terms of a theory’s success at explaining known facts is called “verificationism.” Popper argued that verificationism is equivalent to a belief in induction, and that induction is a fallacy.

This essay grew out of several threads of commentary on Graham Hancock, the author of numerous bestselling books about ancient human pre-history, whose work I had encountered many times over the years. Many millions of people seem to accept Hancock’s radically challenging ideas uncritically, so I thought someone needed to defend mainstream science and put Hancock’s alternative archaeological theories into perspective. What follows is an original essay stitched together from my notes for the show, my postmortem blog about it afterward, my Scientific American column about Hancock’s work, and a few thoughts about the book he published after our studio collision. I like Graham very much as a person, despite our differences over scientific issues, and through correspondence we became friends. He is a warm, thoughtful, caring, generous, and intelligent man whose life’s work I find compelling even while rejecting its central premise, with which this essay shall engage.

the ideological spectrum. Buchanan wrote against Hayek’s evolutionary efficiency claims as well as efficiency claims in rational expectations theories. Hayek’s endorsement of the “liberal dictator” provides the background for Buchanan’s concern with anti-democratic elements of the Mont Pelerin Society. The demise of the Soviet Union has obscured how controversial Nutter’s NBER work was. In the early 1960s, a principles of economics textbook labeled Nutter’s results, reported in Hazlitt’s Newsweek column, as biased. Nutter and Rostow, who differed politically, agreed in their analyses of Soviet growth that Russian culture persisted in spite of the transition to the Soviet Union. Tullock’s long-standing friendship with Popper was critical for the early Virginia School’s analytical egalitarianism in which the motivation of the economist is no different than the motivation of those in the economist’s model. This speaks to ideological motivation. Tullock held that, since economics did not enforce replication, it lacked standing as science and was instead akin to a “racket.”