The first edition was published in 2000 in the Routledge Contemporary Introductions to Philosophy Series. Philosophy of Science: Contemporary Readings (eds Balashov and Rosenberg, 2004) is a companion anthology.
After a chapter on scientific explanation and a chapter on the structure and metaphysics of scientific theories Popper’s contribution is introduced in a chapter on the epistemology of scientific theorizing under the sub-heading Induction as a pseudo-problem: Popper’s gambit.
Unfortunately Rosenberg did not explain Popper’s ideas as an attempt to address some major problems in science and the positivist philosophy of science at the time by reformulating the issue of demarcation to shift attention from meaning to testability because (a) he thought that the verification principle would never work and (b) he thought it was more helpful for working scientists to understand the most effective way to use data than to worry about a criterion for meaning. (It seems that Hempel conceded on (a) in the 1950s).
As to (b) the function of data, Popper argued in favour of deductive testing instead of inductive proof or confirmation because the standard approach was not going to work any better than the verifiability criterion of meaning.
Before making some more comments on the details of Rosenberg’s critique it may be helpful to check how many of the Popperian themes he identified. He did not engage with the theme of non-justificationism and conjectural knowledge (there is no reference to Bartley who was helpful on that aspect of Popper’s epistemology and rationality). He cited Objective Knowledge but did not pursue the theme of objective knowledge itself. The error that Popper called “essentialism”, that is the extended explication of terms, did not arise as an issue in this book. He did not pick up the social turn and Popper’s concern with conventions or “rules of the game”. This aspect of Popperism aroused no comment and there was no citation of Jarvie (2001). There was no reference to Popper’s position on metaphysics and the theory of metaphysical research programs. Popper’s serious work along Darwinian and evolutionary lines was not considered nor the theory of language which he inherited from Buhler, and the growth area of evolutionary epistemology (Bartley and Radnitzky, 1987; Hooker and Hahlweg ).
It is apparent from Rosenberg’s neglect of the Popperian themes that he was not in a position to explain Popper’s contribution in its most robust form to explain why scientists in particular have found his work to be interesting and helpful. Popper is depicted as a failed contributor to the Legend, the project of the positivists and the logical empiricists, rather than an alternative program. Consequently he has fallen into several of the standard errors. It is interesting to note that he only listed three of Popper’s books in the bibliography; The Logic of Scientific Discovery, Conjectures and Refutations and Objective Knowledge.
Rosenberg commenced his critical commentary with reference to Popper’s ideas about deductive testing. He made the strange claim
“Popper held that as a matter of fact, scientists seek negative evidence against, not positive evidence for, scientific hypotheses.” (121)
However Popper was well aware of the existence of “confirmation bias”, for example in the chapter on the sociology of knowledge in The Open Society and its Enemies he wrote
“Everyone who has an inkling of the history of the natural sciences is aware of the passionate tenacity which characterizes many of its quarrels. No amount of political partiality can influence political theories more strongly than the partiality shown by some natural scientists in favour of their intellectual offspring…”. (OSE chapter 23)
Certainly Popper thought that scientists should seek negative evidence but in the case of their own ideas there was no guarantee that they will do so, hence the importance of the social nature of science so that other scientists could compensate for the bias of individuals, provided that they take a critical approach.
“A scientist may offer his theory with the full conviction that it is unassailable. But this will not impress his fellow-scientists and competitors; rather it challenges them; they know that the scientific attitude means criticizing everything, and they are little deterred even by authorities”. (OSE Vol 2, 218)
Popper did not refer to confirmation bias, be referred to “conventionalist strategies” which the defenders of Newton’s theory were using to hold Einstein’s new theory at bay.
Popper mounted logical arguments against theories of induction that attempted to find a way to support or render probably scientific hypotheses. A separate move, not based on logic, was to formulate some proposals for conventions or rules of the game to maximize the critical pressure that is applied to hypotheses, especially by empirical testing.
Taking up the point that the critical approach is a methodological proposal, Rosenberg wrote that Popper stigmatized Freud and Marx on account of the unscientific nature of their theories (122). Certainly Popper was concerned about the status of Freudian theory, although he did not write much about it. In the case of Marx, far from stigmatizing his work he wrote several hundred pages of analysis to pick out the valuable elements (the rejection of psychologism and the beginning of institutional analysis) from the parts which he considered to be dangerous such as the elements of essentialism and prophecy.
Rosenberg then turned his attention to the use of Popper’s ideas by economists, although it is very hard to find economists who have a good understanding of Popper’s ideas. The same applies to the contributors to the post-1980 growth industry of the philosophy and methodology of economics. He concluded that
“when it comes to economics, Popper’s claims seem to have been falsified as descriptions and to have been ill-advised as prescriptions. The history of Newtonian mechanics offers the same verdict on Popper’s prescriptions…Popper’s one-size-fits-all recipe, “refute the current theory and conjecture new hypotheses”, does not always provide the right answer” (123)
It is more correct to say “test the current theory, discover new problems and go to work on them with new hypotheses and imaginative criticism (and tests)”.
Popper did not provide a one-size-fits-all recipe, he advocated a critical approach with several forms of criticism – logic, tests, problem-solving capacity, consistency with other theories, consistency with the metaphysical research program – and the kind of criticism that is appropriate depends on the theories under investigation and the aspect of the theory that is under scrutiny at the time.
Strangely, Rosenberg regarded Eddington’s eclipse observations as a confirmation of Einstein’s theory; of course Popper knew that the result was a triumph for Einstein in comparison with Newtonian mechanics but that did not mean that Einstein’s theory was proved, confirmed or verified in the final and definitive form required to justify the demands of justificationists.
Rosenberg asked:
“What can Popper say about theories that are repeatedly tested, whose predictions are borne out to more and more decimal places, which make novel striking predictions that are in agreement with (we can’t say “confirmed by”) new data?”
He can say that they are very powerful and beautiful theories and quite likely the best that we have at the present time but that is no guarantee that anomalies will not appear (if they have not done so already), rivals may appear in the way that Einstein challenged Newton and not for the first time a theory that was considered to be the end of the road will turn out to be another milestone in the progress of science. On a point of detail, what theory at the present time is considered to be confirmed in the way that Rosenberg seems to think that Einstein’s theory was confirmed (up to the time of this book, 2010)? What is the current status of Einstein?
