Are scientific research programs rational?

6 The challenge of history and post- post-positivism

6.3 Are scientific research programs rational?

It is not surprising that many philosophers of science and scientists have been unhappy with an account of science such as Kuhn’s, which denied its progress, its cumulativeness, and its rationality. Even as he provided import-ant philosophical foundations for claims such as Kuhn’s, Quine was himself unhappy about the image of science Kuhn’s work advanced. Indeed, Kuhn himself in later writings seemed to reject the radical interpretation of The Structure of Scientific Revolutions which had become predominant, and which was presented in Section 6.1 above.

Among the philosophers of science who sought an account of scientific change that accorded it rationality, one of the most visible was Imre Lakatos, a protégé of Karl Popper. It will be useful to sketch Lakatos’ account, which he called “the methodology of scientific research programs”, both to illus-trate how some philosophers of science responded to Kuhn, and how they missed the force of his radical critique of progress in science.

According to Lakatos, scientific theories are components of larger cogni-tive units: research programs. Research programs are something like Kuhn’s paradigms. But unlike a paradigm, a research program consists of state-ments, propositions, formulae, and does not also include artifacts, experi-mental devices or distinctive measuring equipment associated philosophical theses and other non-descriptive items. First, there is the research program’s hard core: a set of assumptions about the world that are constitutive of the program and cannot be surrendered without giving it up altogether. For example, the Newtonian research program’s hard core includes the inverse square law of gravitational attraction, while Darwinism’s includes some-thing like the PNS identified in Chapter 4. Surrounding the hard core is what Lakatos called its “protective belt”, a set of further claims of the theory which function as auxiliary hypotheses. On the one hand, these theories are needed to apply the components of the hard core to explanation and predic-tion, and on the other hand, they may be changed to avoid treating com-ponents of the hard core as falsified by evidence. Darwin’s own quite mistaken theory of heredity is a good example: it was surrendered without any harm to the research program of evolutionary biology. Mendel’s theory

was added to the protective belt, with important consequences for the hard core. Two further components of a research program are the positive and negative heuristics, which include methodological rules that guide changes in the protective belt and enjoin revision of the hard core. The positive heuristic of Newtonian mechanics will include the injunction expressed in the principle of sufficient reason: “every event has a cause: search for it!”.

The negative heuristic will deny “action at a distance” – causation without spatiotemporal contact (except by gravity).

A research program can be progressive or degenerate. It is progressive if over time its theories enable the scientists employing it to make new predic-tions, or at least to accommodate data already known but not employed originally to formulate the hard core of the program. Honoring the influence of Popper, Lakatos recognized that new predictions arise when scientists respond to the falsification of a program’s predictions, by making changes in the protective belt, the positive or the negative heuristic. If these changes enable them to derive novel expectations which are then realized, the research program is vindicated as progressive. The discoveries of Neptune and Uranus are classic examples of novel predictions in the Newtonian research program.

Responses to falsifications which merely preserve the hard core without conse-quent new vindicated predictions are stigmatized as ad hoc.

When a program ceases to generate new predictions, and/or persistently invokes ad hoc changes in the protective belt or elsewhere, it is said to have become degenerate. According to Lakatos, the rationality of scientific change consists in this: scientists persist in the articulation (to use a Kuhnian term) of the research program so long as it remains progressive. Once it has ceased to do so for long enough, scientists begin to challenge some or all of the components of the original hard core, thus creating a new research program, distinguished from the degenerating one by a different hard core. Disci-plines are characterized by a succession of research programs: each such program moves from progressive to degenerate, and is replaced by a new more adequate one accommodating its predecessor’s novel predictions. This is progress across research programs on Lakatos’ view, and not merely the succession of alternative paradigms Kuhn’s account of scientific change sug-gests. A discipline which evinces Lakatos’ model of research programs, their internal development, and their succession, is a science which proceeds in accordance with rational standards of belief change. By this standard, the natural sciences appear to be safe from reproach, while many research pro-grams in social science, among them the ones Popper stigmatized as pseudo-science – Marxian dialectical materialism, Freud’s psychodynamic theory – are probably degenerate.

Has Lakatos really provided an account of rational scientific change? The follower of Kuhn will hold that, as it stands, the differences with Kuhn’s account of scientific change are cosmetic except where Lakatos simply begs the question against Kuhn’s arguments. Lakatos neither does nor can give us a litmus test for when it becomes unreasonable to cling to a degenerating

research program, still less a measure that would enable scientists to rank programs for progressivity. It is easy for a historian of science such as Kuhn to identify research programs which degenerated for a long period while retaining the confidence of scientists and which then began again to be pro-gressive. Without such a litmus test, clinging to a degenerating research program may not be stigmatized as irrational, just as Kuhn argued. One might even count as a single progressive research program in physics the tra-dition that extends from Aristotle to Einstein, or at least as one worthy of rational support despite its period of degeneration during the temporary heyday of Newton’s occult force, gravity.

Lakatos’ theory faces problems of counting new or novel predictions to decide whether successive or competing research programs are in fact pro-gressive. Of course, a follower of Lakatos could try to deal with some of these problems. But it remains to be seen whether one could do so without ignor-ing Quine’s insights about theory testignor-ing and empirical content. The litmus test of scientific progress is, according to Lakatos, novel prediction. But why is this? We can rule out one apparently attractive answer immediately: the goal of science is improvement in technological application, and novel pre-diction is the best means to attain it. Pretty plainly, many scientists, for example, cosmologists and paleontologists, do not share this aim of techno-logical application. Some among them, many biologists, hardly ever seek novel predictions. To suggest that science as an institution embraces aims separate from those of individual scientists is not unreasonable of course, but a reason needs to be given for the goal we do attribute to it. What is more, even if technological application were the goal of science, it is by no means clear that a single-minded focus on novel prediction is the sole or always the best means to attain it.

As noted above, much of the actual history of science shows that research programs which for a time may degenerate, failing for long periods to provide novel predictions, end up doing better by way of novel prediction than their temporarily progressive competitors. In so doing, they reveal that the role of novel predictions is not in fact as decisive among scientists as Lakatos’

methodology requires. Consider the vicissitudes of the wave- and particle-theories of light. The theory that light is a particle degenerated badly in the nineteenth century, owing to the experiments of Fresnel. This scientist argued that if light is composed of waves which interfere and reinforce each other, then there should be a bright spot at the center of a spinning disk, and no such spot if light were composed of particles. No one had ever performed the exper-iment to see if such a bright spot exists. The confirmation of Fresnel’s novel prediction was striking evidence for the progressivity of his theory and the degeneracy of the particle theory. Yet a hundred years later, the particle theory’s claims were vindicated in the shape of the photon.

Of course, Lakatos’ account of scientific change can accommodate this history, according rationality to those who stuck with the research program of the particle theory throughout its period of degeneracy. But that is part of

the problem. It is too easy for his account to do so. The other part of the problem is that it was not owing to the search for any technological pay-off that Fresnel made his novel prediction; indeed, there was none of any importance.

So, why did Fresnel seek this novel prediction, and why did it have the effect of eclipsing the particle theory’s research program for the better part of a century? Here is another answer Lakatos might have given that we will have difficulty accepting: science seeks theories with greater empirical content, and research programs whose theories make novel predictions that are vindicated, and have greater empirical content than ones which fail to do so. To begin with, this claim must be understood as one not about novel prediction in general, but novel prediction of observable phenom-ena. Otherwise we are not talking about empirical content, but something else (theoretical content, whatever that is). This requires a controversial distinction between observational and theoretical vocabularies that Kuhn would reject. It also requires a way of comparing theories for empirical content. But as Quine’s arguments prove, distinguishing the empirical content of a theory from its logical, syntactical, mathematical or other sort of non-empirical form is far from an easy task, if the distinction is coherent at all. What is worse, if theory choice is underdetermined by observation, as Quine insists, then it is evident that there can be competing, or for that matter successive, research programs, or at least theories, in a discipline with equal empirical content. And yet we never see the proliferation of such research programs or theories in the history of the sciences once the disciplines emerge from what Kuhn called the “preparadigm period”. It must be that something else is determining theory choice. This is, so to speak, where we came in on the story, of course. For we ended Chapter 5 searching for what determined the actual history of theory, research-program – or paradigm – choice in light of the fact that observation apparently does not suffice to do it.

Suppose we “privilege” novel prediction as the means to scientific progress by articulating an epistemological theory, an account of what knowledge consists in, that makes novel prediction a (perhaps uniquely) reliable indicator of justified true belief. Then of course in so far as science seeks knowledge, vindicated prediction will be the means to attain it, and a scientific discipline’s attachment to novel predictions will turn out to be rational. Why, an exponent of Kuhn will ask, should we “buy into” this epistemology? Quine and other naturalists would hold such an epistemology is not a “first philosophy” prior to science, which can stand in judgment of its rationality and epistemic progress. It is part and parcel of science. If so, embracing it without argument will simply beg the question against other epistemologies. But, if first philosophy is impossible, as the naturalist holds, there is no neutral point of view from which to adjudicate competing episte-mologies prior to applying them to assess the rationality of science. Of course, Kuhn would argue that epistemologies are components of

para-digms, and unlike Lakatos, he would decline to divide them up into cores, belts and heuristics, each separably identifiable and changeable without impact on the other parts. Indeed, according to Kuhn, the central place of predictive novelty, especially in Newtonian science, is like the philosophy of logical positivism as a whole. Both are devices with which the Newtonian paradigm is defended.

Lakatos’ methodology of scientific research programs will not provide the assurance we seek that, despite Kuhn’s historical evidence, science is after all cumulative, progressive, or even rational. Thus, in this chapter, the stakes of the bet about the rationality of induction made at the end of Chapter 5 have been raised even higher. At the end of that chapter we faced the problem that the succession of scientific theories was not fully justified or for that matter explained by their relationship to observational evidence which is widely supposed to vindicate them. Now we are faced with the prospect that in addition to not being controlled by data, whatever it is that does control the course of science may not even be rational.

Summary

According to Kuhn, the unit of scientific thought and action is the para-digm, not the theory. Specifying what a paradigm is may be difficult, for it includes not just textbook presentations of theory, but exemplary problem-solutions, standard equipment, a methodology, and usually even a philo-sophy. Among the important paradigms of the history of science have been the Aristotelian, the Ptolemaic, and the Newtonian in physics. Chemistry before Lavoisier, and biology before Darwin, were “preparadigm” disci-plines, not yet really “scientific”, for without the paradigm there is no

“normal science” to accumulate information that illuminates the paradigm.

The paradigm controls what counts as data relevant to testing hypotheses.

There is, Kuhn argued, along with other opponents of empiricism, no obser-vational vocabulary, no court of final authority in experience. Experience comes to us already laden with theory.

Crisis emerges for a paradigm when a puzzle cannot be solved, and begins to be treated like an anomaly. When the anomaly begins to occupy most of the attention of the figures at the research frontier of the discipline, it is ripe for revolution. The revolution consists in a new paradigm that solves the anomaly, but not necessarily while preserving the gains of the previous para-digm. What the old paradigm explained, the new one may fail to explain, or even to recognize. Whence it follows that scientific change – the succession of paradigms – need not be a progressive change in the direction of succes-sive approximation to the truth.

Observation does not control inquiry, rather inquiry is controlled by sci-entists, articulating the paradigm, enforcing its discipline, assuring their own places in its establishment, except at those crucial moments in the history of science when things become unstuck and a revolution ensues – a

revolution which we should understand as more in the nature of a palace coup than the overthrow of an old theory by one rationally certifiable as better or more correct.

This picture of science is hard to take seriously from the perspective of empiricism, historical or logical. It gained currency among historians, socio-logists and psychosocio-logists, at the same time as, and impact because of the influence of the philosopher W.V.O. Quine, who unraveled the tapestry of philosophical theories of science as cumulative observational knowledge about the nature of reality.

Quine began by undermining the distinctions: between statements true as a matter of logic or form versus statements true as a matter of content or empirically observable fact. It may be surprising but once this distinction, well known to philosophy since Kant, is surrendered, everything in epis-temology and much in the philosophy of science becomes unstuck. The denial of this distinction gives rise to holism about how theory confronts experience, and to the underdetermination which spawns Kuhn’s approach to the nature of science. But it also gives rise to a stronger commitment to science by some philosophers than even to philosophy, or at least it gives rise to the idea that we must let contemporary science guide our philosophy, instead of seeking science’s foundations in philosophy. Philosophers, largely followers of Quine, who have adopted this view label themselves “natural-ists”, a term unfortunately that others, especially sociologists adopting incompatible views, have also adopted.

Naturally, neither Quine nor other philosophers are prepared to accept Kuhn’s apparent subjectivism about science as the correct conclusion to draw from their attack on empiricism. This placed on the table a new problem, beyond Hume’s problem of induction. The problem remains of finding a foundation for science as objective knowledge consistent with these arguments. The recent vicissitudes of work on this problem is the subject of the next chapter.

Study questions

1 Which among various approaches to the study of science – philosophy, history, sociology – is the more fundamental? Do these disciplines compete with one another in answer to questions about science?

2 How would a defender of Kuhn respond to the claim that the history of technological progress which science has made possible refutes Kuhn’s claim that science is not globally progressive?

3 Kuhn’s arguments against the existence of a level of observation free from theory date back to the 1950s. Have subsequent developments in psychology tended to vindicate or undermine his claims?

4 Quine once said “philosophy of physics is philosophy enough”. Give an interpretation of this claim that reflects Quine’s claims about the rela-tion between science and philosophy.

5 Is naturalism question-begging? That is, does according the findings of science control over philosophical theorizing rest on the mere assertion that science is our best guide to the nature of reality?

6 Apply Lakatos’ methodology of scientific research programs to one or another of the social sciences, identify the hard core, protective belt, positive and negative heuristic. Don’t infer that if you have located them, the research program must be a “scientific” one. Why not?

Suggested reading

Every student of the philosophy of science must read T.S. Kuhn, The Struc-ture of Scientific Revolutions. Other important works of Kuhn’s include The Essential Tension which includes important reflections on the earlier book.

Balashov and Rosenberg, Philosophy of Science: Contemporary Readings, reprint a paper by Kuhn that appeared in this later work. D. Shapere, “Review of Structure of Scientific Revolutions”, is an important review of Kuhn’s book which was originally published in Philosophical Review (1964). This paper is anthologized in Balashov and Rosenberg. Along with other commentaries on Kuhn it also appears in G. Gutting, Paradigms and Revolutions. A Festschrift for Kuhn containing several important retrospective papers is Horwich, World Changes: Thomas Kuhn and the Nature of Science.

Another significant examination of the history of science with implica-tions for its philosophy is Norwood Russell Hanson, Patterns of Discovery.

His was among the earliest attacks on the empiricists’ distinction between observational and theoretical terms. One chapter of this work is reprinted in Balashov and Rosenberg.

P. Feyerabend, Against Method, summarizes a series of papers in which the author champions a philosophically informed version of the most radical interpretation of Kuhn’s views. An influential paper by Feyerabend on reduction in science, “Explanation, Reduction, and Empiricism”, is also reprinted in Balashov and Rosenberg.

Quine’s attack on empiricism emerges in From a Logical Point of View which contains his extremely influential essay, “Two Dogmas of Empiri-cism”. This, too, is required reading for anyone interested in the philosophy of science. Quine, Word and Object, is a later work that deepens the attack on empiricism, and develops the doctrine of underdetermination so influential on Kuhn and others. Balashov and Rosenberg’s anthology includes “Two Dogmas of Empiricism”.

Naturalism is expounded and defended in P. Kitcher, The Advancement of Science. Lakatos develops his account of scientific change in “Falsification and the Methodology of Scientific Research Programs”, in a work containing several important papers on Kuhn’s books, Lakatos and Musgrave, Criticism and the Growth of Knowledge. Another important post-Kuhnian account of scientific change, which is highly sensitive to the problems Lakatos’ account faces is Larry Laudan, Progress and its Problems.