Jeffrey Friedman has attempted to make a case for limiting state social engineering that is based on the skeptical epistemology of Sir Karl Popper. But Popper's epistemology is flawed, both in its rejection of a priori theorizing and its insistence on empirical falsification rather than confirmation. Classical liberalism of the sort that Friedman advocates requires, as its basis, positive knowledge of economics and social reality—not Popperian skepticism.

Le présent article veut (1) montrer que la théorie qualitative de la vérisimilarité exposée par Karl R. Popper dansConjectures and RefutationsetObjective Knowledgeest compatible avec sa méthode des conjectures, corroborations et réfutations; (2) faire voir pourquoi cette théorie apparaît néanmoins trop forte d'un point de vue intuitif; (3) montrer comment le système poppérien permet de contourner la preuve formelle présentée par Pavel Tichy en 1974 à l'encontre de la théorie qualitative de la vérisimilarité; (4) proposer une nouvelle définition de la vérisimilarité (...) qui apparaisse non seulement logiquement fondée, mais plus intuitivement acceptable et davantage liée à la méthodologie poppérienne que la définition originelle. (shrink)

In this paper, three theories of progress and the aim of science are discussed: the theory of progress as increasing explanatory power, advocated by Popper in The logic of scientific discovery ; the theory of progress as approximation to the truth, introduced by Popper in Conjectures and refutations ; the theory of progress as a steady increase of competing alternatives, which Feyerabend put forward in the essay “Reply to criticism. Comments on Smart, Sellars and Putnam” and defended as late as (...) the last edition of Against method. It is argued that, contrary to what Feyerabend scholars have predominantly assumed, Feyerabend's changing attitude towards falsificationism—which he often advocated at the beginning of his career, and vociferously attacked in the 1970s and 1980s—must be explained by taking into account not only Feyerabend's very peculiar view of the aim of science, but also Popper's changing account of progress. (shrink)

In this paper, I argue that, just as the problem of unconceived alternatives provides a basis for a New Induction on the History of Science to the effect that a realist view of science is unwarranted, the problem of unconceived objections provides a basis for a New Induction on the History of Philosophy to the effect that a realist view of philosophy is unwarranted. I raise this problem not only for skepticism’s sake but also for the sake of making a (...) point about philosophical argumentation, namely, that anticipating objections to one’s claim is not the same as supporting one’s claim. In other words, defending p from objections does not amount to support or evidence for p. This, in turn, presents dialectical and pragma-dialectical approaches to argumentation with the following question: does proper argumentation require that arguers anticipate and respond to unconceived objections? (shrink)

The concept of approximate truth plays a prominent role in most versions of scientific realism. However, adequately conceptualizing ?approximate truth? has proved challenging. This article argues that the goal of articulating the concept of approximate truth can be advanced by first investigating the processes by which science accords theories the status of accepted or rejected. Accordingly, this article uses a path diagram model as a visual heuristic for the purpose of showing the processes in science that are involved in determining (...) a theory's status. This ?inductive realist? model of theory status then serves as a starting point for explicating an inductive realist view of approximate truth that, it is argued, can explain instances of the success of science, but does not (1) require science's theories to be strictly true in any world or (2) require a metric for measuring how close an approximately true theory is to some strictly true theory. To show the advantages of the inductive realist approach to approximate truth, an example of a major success story of science, the successful eradication of smallpox, is reviewed and then explained. (shrink)

In a short 1997 book entitled Simplicity as Evidence of Truth, the Oxford philosopher Richard Swinburne has put forward the following thesis summarily: ‘… for theories (of equal scope) rendering equally probable our observational data (which, for brevity I shall call equally good at “predicting”), fitting equally well with background knowledge, the simplest is most probably true’.

The logical interpretation of probability, or "objective Bayesianism'' – the theory that (some) probabilities are strictly logical degrees of partial implication – is defended. The main argument against it is that it requires the assignment of prior probabilities, and that any attempt to determine them by symmetry via a "principle of insufficient reason" inevitably leads to paradox. Three replies are advanced: that priors are imprecise or of little weight, so that disagreement about them does not matter, within limits; that it (...) is possible to distinguish reasonable from unreasonable priors on logical grounds; and that in real cases disagreement about priors can usually be explained by differences in the background information. It is argued also that proponents of alternative conceptions of probability, such as frequentists, Bayesians and Popperians, are unable to avoid committing themselves to the basic principles of logical probability. (shrink)

In September 2007, more than 100 philosophers came to Prague with the determination to approach Karl Popper's philosophy as a source of inspiration in many areas of our intellectual endeavor. This volume is a result of that effort.