In the philosophical debates which followed the collapse of the foundationalistic epistemology of the empiricist consensus, many philosophers were persuaded by "theory-ladeness" and "holism" to abandon the old hope for an account of a normative scientific rationality which would reveal a timeless set of rules, applicable to all sciences, for determining what scientific beliefs the ideal, rational scientist should accept. The empiricists had been misled by their drive to create a sharp distinction between "scientific" and "pseudo-scientific" beliefs into thinking that there was some one set of such standards of scientific rationality which were common to all the genuine sciences and which were ignored or violated in the unjustified cognitive claims of the "pseudo-sciences." Thus such putative standards could not be discipline specific, varying from one field of science to another, nor could they change throughout the historical development of science. Moreover, as empiricists, defenders of the old consensus held to a sharp distinction between descriptive claims, which purport to tell how things are (the "facts") and must be justified by appeal to experience, and normative claims which claim to stipulate how things should be ("values"), which therefore lie beyond the reach of empirical confirmation or refutation. Ever since Hume, empiricists had been committed to the supposition that "values" could not be derived from "facts"; i.e. how things are can never serve as a premiss from which one can deduce how things should be. This empiricist commonplace was often expressed by saying "you cannot derive an 'ought' from and 'is'." Philosophers who violated this stricture were branded as having committed the "naturalistic fallacy."
As the collapse of foundationalism opened the field to new positions on the manner in which scientific beliefs attain the "authority" they do in fact enjoy in the contemporary world, philosophers defended a variety of positions that can be arrayed in a kind of "spectrum" from "right" to "left" with respect to the authority accorded some form of "scientific rationality." This chaotic state of affairs has now come to be called "the rationality crisis." On the extreme "left" Paul Feyerabend took up the stand of "epistemological anarchy," proclaiming that with respect to permissible methods for gaining acceptance as "scientific belief," "Anything goes!" Feyerabend had come to this stand via a Popperian youth, and the idea that theories could, should, and are falsified remained a deep strain in his philosophy. Although he took up a stand which was called "irrationalist" with respect to science, Feyerabend did have cleverly defended philosophical arguments which influenced many, in spite of their disagreement with his overall position. He wrote simultaneously with Kuhn, and the two were colleagues for a while at Berkeley, but he also had sharp disagreements with Kuhn's approving attitude towards what he had called "normal science." As a vestigial Popperian Feyerabend strenuously objected to Kuhn's defense of the monopolistic status of a reigning paradigm during "normal science." The absence of rival theories -or the refusal to give them any serious consideration as long as the accepted paradigm remains free from anomalies- presents a restricting barrier to the growth of knowledge. However, like Kuhn, Feyerabend accepted -to the fullest- both the theory ladeness of all "facts" and the holistic view of language meaning. Thus he reasoned from "theory-ladeness" of facts to the conclusion that the "facts" most likely to refute any given theory will not be generated by that theory, but rather by its rivals. Therefore, if knowledge grows by refuting the old, the most rational way to make knowledge grow is to maximize the number of competing theories. Methodological rules, however, have the effect of restricting the permissible contending rivals (as well as to determine such matters as funding, institutional support, etc.) to those rivals deemed sufficiently "orthodox" and cutting off, before they have a chance (or funding or institutional support) to grow, those theories which are regarded as "unorthodox." Feyerabend was thus led to conclude that "liberation" entails rejecting all constraining rules of acceptable methodology, or that, in short, "anything goes."
However, aside from Feyerabend, few philosophers were very "joyful" over the seeming collapse of rationality. Indeed, admitting as much would put philosophy of science -as traditionally conceived- out of business. There was, however, another group of scholars studying science whose fortunes (and status) were enormously enhanced by these developments. They were, and are, the "sociologists of science." To this audience, the Kuhnian challenge to empiricism was a waking call to a grand new day. This group took the collapse of foundationalism for granted, along with the usual commitments to theory ladeness and holism. However, they asserted that these conclusions do not imply that there is no rationality for deciding which theory to choose, but rather that the rationality for which philosophers had searched -one based on reason and empirical evidence- was not to be had. Indeed, Kuhn paved the way with his account of a paradigm shift in explicitly sociological terms. However, Kuhn's conception clearly favored the notion that while it was the subjective values of individual scientists comprising the "professional community" which -one by one- led each to make the shift, those values were the values of the community of scientists per se. As such, the values operative in Kuhn's account of rationality were predominantly "internal" to science Furthermore, Kuhn speaks of these values as more or less stable through history and across all disciplines. They would include such virtues as precision, scope, novel predictions, fertility in suggesting new lines of research, simplicity, etc. However, Kuhn does acknowledge -though he does not explore- that scientists are also influenced in their theory-choice decisions by factors "external" to science, beyond those values which characterize the restricted community of professional researchers, to those inherent in society at large or some dominant group within that society. Thus the new discipline of "social studies of science" was born with a banquet of "externalist" options for characterizing the reasoning processes which drive the choice of theories in science, each with its own ideological axe to grind. In a breathtaking leap from the conclusion that observational evidence and reasoning cannot determine theory choice, many arrived at the conclusion that observation and logic have nothing -or virtually nothing- to do with theory choice. On this reading, the lesson to be learned from the collapse of foundationalism is that what passes as scientific knowledge is the product of a process entirely governed by social forces and is quite independent of "the way the world is," the very notion of which is considered a ludicrous remanet of discredited foundationalism. Empirical underdetermination, they concluded,. implies that any theory can be made to "fit" with any body of evidence, so empirical evidence cannot even be relevant to theory choice. From this source the debates now known as "The Science Wars" have now sprung.
Philosophers of science, however, were not all quite prepared to surrender rationality to the sociologists and go out of business. While most were persuaded that the old ideal of a normative rationality based on empirical evidence and reasoning could never determine scientific theory choice, one could still hope for a rationality in which such factors at least narrowly constrain the permissible options. Social factors play a role, no doubt, most were willing to concede, particularly in the early stages of a theory's initial reception, but achievements of scientific knowledge cannot be regarded as purely a "social construction" as the sociologists of science maintain For some of these philosophers the best hope for a resurrection of an internalist scientific rationality was thought to lie in a defense of the older view that there is a "way the world is," and that as scientific knowledge grows and changes, our scientific account of the world approaches ever more closely to the goal or describing that reality, a relationship to which we refer with the notion of "truth" or "approximate truth.".. These philosophers are realists. Other philosophers sought to salvage an internalist account of scientific rationality without appeal to the metaphysically problematic notion of a "way the world is" and the accompanying notion of "truth" as a correspondence between reality and our scientific beliefs about reality. They are the anti-realists. Among antirealist defenders of scientific rationality, three who drew a great deal of attention in the 1980's (and continue to do so) were Bas van Frassen (Princeton), Arthur Fine (Northwestern), and Larry Laudan (who has never enjoyed a long tenure at any one institution)..