Post-Kuhnian Models of the Practice of Science

The Kuhn-Popper Debate

In 1965, Karl Popper and Thomas Kuhn meet in London at the International Colloquium in the Philosophy of Science, and while the two made initial attempts to downplay their differences, it soon became apparent that they disagreed in the most fundamental of ways. For Popper, Kuhn's position seemed to undercut the objectivity of science and to threaten the very rational basis of the scientific enterprise. Kuhn's stress on paradigms and revolutions seemed to make scientific reasoning more a phenomena of group psychology and even metaphysical faith than the objective, independently testable standards that Popper believed science should abide by. While Popper was willing to concede that what Kuhn described as "normal science" did go on, to conduct research in this way was to "fail" at its rational standards.

Kuhn, on the other hand, objected to being labeled an irrationalist or a fideist. There are good reasons for a scientist to continue to hold to a theory after an initial failure to obtain the desired experimental results. He insisted that Popper's normative standards of falsification really only apply to certain revolutionary moments of science, not the large majority of its daily practice. Indeed, even in some revolutionary cases the new paradigm replaced the old one before it was successfully refuted. While, Kuhn admitted that in one sense he might be judged a relativist, in another sense he was not. Essentially, Kuhn insisted, that while he held that there can be no theory-independent access to what is "really there," he nonetheless held that science has made progress in ways that could be seen across paradigms. He insisted that the search for an absolute truth to scientific findings is counter-productive and really matters very little in the long-run. 

Imre Lakatos--Lakatos sought to bridge the gap between the descriptive model that Kuhn offered and the prescriptive one that Popper taught. In what he called "the methodology of scientific research programmes," he stressed that scientific research is really a series of theory-systems, that is a changing set of experiments and ideas that contain a "hard core" (i.e. the central assumptions) which the researchers involved attempt to protect via a network of auxillary assumptions, what Lakatos calls its "negative heuristic."  

Rather than describe the research "programme" as true or false, one should see it as either progressing or degenerating. Commitment to a theory can offer important epistemic payback, provided that the reworking of the system continues to offer progress (a "positive heuristic") via new information, continued testability, more precision, and so on. However, once a programme fails to do so and only makes ad hoc changes to protect itself, it begins to degenerate.  A degenerating programme sounds its death knells once its encounters a progressive one with a rival hard core of theory.

Paul Feyerabend--Feyerabend, on the other hand, argued in works like Against Method that scientists never actually follow the methodological rules set down as normative for science, and indeed in many revolutions to do so would have impeded actual progress. To insist that new theories are consistent with older theories gives an "aesthetic" privilege to the past. The criteria of falsification is especially misguided since no theory with any real explanatory power and interest can account for all the facts. He recommended a "scientific pluralism," in which practitioners of various theories are forced to better articulate their models through robust comparison. Feyerbend also thought claims of incommensurability could lead to a retarded progress; better to indulge in something like "scientific anarchism." He even held that science and society needed something like a legal wall of separation since the arrogance of science closed itself off too easily to other mythical descriptions of reality. Feyerabend, perhaps in a catty mood, called Lakatos his fellow "anarchist" and claimed that Lakatos' model was really his own using other terminology.



Social Construction--Social constructionists of science are perhaps the disciples Kuhn never wanted. To say that something is socially constructed is to argue that everyday life can only be interpreted as meaningful by members of a social group. This position can take moderate and radical forms. A moderate approach to social constructivism stresses that the truth or falsity of a scientific claim is found within social appeals and practices, not in extra-theoretical appeals. David Bloor, for example, advocated what he called the "strong programme" in the sociology of scientific knowledge, namely that all knowledge must have a social element because all perception is theory-laden. In this way, Bloor is a Kantian--science cannot finally access the Ding an Sich, the "thing in itself." Thus, there are no "supra-social standards" by which one may judge the content of science. Bloor sets out the strong programme this way:

1. It would be casual, that is, concerned with the conditions which bring about belief or states of knowledge. Naturally there will be other types of causes apart from social ones which will cooperate in bringing about belief.

2. It would be impartial with respect to truth and falsity, rationality or irrationality, success or failure. Both sides of these dichotomies will require explanation.

3. It would be symmetrical in its style of explanation. The same types of cause would explain, say, true and false beliefs.

4. It would be reflexive. In principle its patterns of explanation would have to applicable to sociology itself. Like the requirement of symmetry this is a response to the need to seek for general explanations. It is an obvious requirement of principle because otherwise sociology would be a standing refutation of its own theories.

Science sees what its members are trained to see, and sociologists of science would seek not to make judgments as to the truth or falsity of its findings because truth and falsity can never be ascertained outside social conventions of understanding, including that of the sociologist of science. A more radical approach to social constructivism, such as that taken by Bruno Latour, Michel Callon, or Steve Woolgar, insists that scientific networks are a self-contained reality, that science is about its practice not a real world outside itself--in a sense, the "real world" is created by social practice and theory. Another expression of radical constructivism can be seen in feminist science criticism. Social constructionists pay close attention to the metaphors that inform scientific theory and dialogue, metaphors which they charge reveal much about the social dimension of the practice. Feminists critics, such as Sandra Harding, charge that the rhetoric of much male science (including non-feminist female science) is full of imagery of power, rape, and abuse, and this imagery reveals the epistemic limits of its findings.

According to Larry Laudan, as of 1981 the state of the search for a philosophy of science and its history can be said to be that:


(1) Theory transitions are generally non-cumulative, i.e., neither the logical nor empirical content (nor even the confirmed consequences) of earlier theories is wholly preserved when those theories are supplanted by newer ones. 

(2) Theories are generally not rejected simply because they have anomalies nor are they generally accepted simply because they are empirically confirmed. 

(3) Changes in, and debates about, scientific theories often turn on conceptual issues rather than on questions of empirical support.

(4) The specific and 'local' principles of scientific rationality which scientists utilize in evaluating theories are not permanently fixed, but have altered significantly through the course of science.

(5) There is a broad spectrum of cognitive stances which scientists take towards theories, including accepting, rejecting, pursuing, entertaining, etc.  Any theory of rationality which discusses only the first two will be incapable of addressing itself to the vast majority of situations confronting scientists. 

(7) Given the notorious difficulties with notions of 'approximate truth'- at both the semantic and epistemic levels- it is implausible that characterizations of scientific progress which view evolution towards greater truth-likeness as the central aim of science will allow one to represent science as a rational activity.

(8) The co-existence of rival theories is the rule rather than the exception, so that theory evaluation is primarily a comparative affair. 



Realism and Antirealism

At the heart of the Pandora's box that Kuhn, perhaps unwittingly and unintentionally, opened are the related questions as to whether the various sciences examine a common reality, whether an actual order is uncoverable in the universe other than the one that a theory imposes on it, and whether theories can be said to be "real" in any fundamentally actual manner.  Janet A. Kourany suggests that this debate can be formulated this way:


1.  Do the theories of science give a literally true account of the way the world is? Or are they mere calculating device, useful fictions, convenient methods of representations, only empirically adequate but not true, or only true in some non-literal sense?

2.  Under what conditions is it reasonable to accept a theory on a realistic interpretation (as literally true) rather than on an instrumentalist interpretation (as not literally true, but convenient for summarizing, systematizing, deducing, and so on a given body of information)?

3.  Under what conditions is it reasonable to accept the entities postulated by a theory (and this includes processes, states, fields, and the like) as real existents rather than as mere hypothetical entities?

The two broad camps of realism and anti-realism can be divided by those who affirm that science in some way describes the actual world and those who say that it is at best always a description of our interactions with the world.

                           Realism                                                                 Antirealism

Grover Maxwell--The line between observation and theory is always an arbitrary one; and all objects could be potentially observable. What counts as observable is itself a theoretical question, so the distinction has no real value.  

Bas van Fraassen--"Empirical adequacy" is the best a scientist can claim about any theory; the observation-theory distinction can be made though admittedly "observation" is always a vague predicate, which can only be used in a functional manner.

The Ultimate Argument fails because the success of science is like Darwinian evolution; the strongest theories survive due to their empirical adequacy in handling the physical world.

Hilary Putnam--The Ultimate Argument--If the mathematical and physical experiences of science are not about the actual world, then the success of science is a "miracle," which is simply ludicrous. 
Philip Kitcher--A consistency exists between observational findings and theories because of the comparative nature of science. One is always checking one's theory against the observations. Larry Laudan--The history of science shows numerous examples of theories that were successful yet not actually referential to objects we now believe to exist; likewise, a number of examples can be offered of unsuccessful theories that did refer to genuine objects in the world.
Alan Musgrave--The realist is taking no more risk by betting on the actual real findings than the antirealist is by relying on empirical adequacy. Realism offers the most epistemic benefit. Antirealists haven't explained why some theories survive and others do not.

Ian Hacking--Experimental realism--Scientists form beliefs about objects by interacting with them. Theoretical terminology refers to actual unobservable referents, even if the terminology shifts over time. Beliefs about what we observe and cannot yet observe are similar, so we need not commit to the referential truth of theories to commit to the observational truths of experimentation.

Arthur Fine--Natural Ontological Attitude (NOA)--Accepting the results of science as "true" in an ordinary day-to-day manner does not commit one to the long-term survival of its truth or to the ability of science to uncover the final "Truth" of existence.

Bloor, David. Knowledge and Social Imagery. 2nd ed. Chicago: U of Chicago P, 1991.

Kourany, Janet A. Scientific Knowldege: Basic Issues in the Philosophy of Science. Belmont: Wadsworth, 1987.

Laudan, Larry. "A Problem Solving Approach to Scientific Progress." Scientific Revolutions. ed. Ian Hacking. Oxford: Oxford UP, 1981. 


"All manner of thing shall be well/ When the tongues of flame are in-folded/ Into the crowned knot of fire/ And the fire and the rose are one." -- T.S. Eliot, Little Gidding