THOMAS KUHN ON REVOLUTION AND PAUL FEYERABEND
BOOK VI - Page 7
Feyerabend on Relativism, Historicism, and Realism
The consequential outcome of the lengthy debate between Hanson and Feyerabend results less from their discussion about current quantum theory than from their discussion about the future of microphysics, if not also the future of Feyerabend’s philosophy. Feyerabend found himself in the unenviable position of having to wait for some future physicist to produce a future scientific revolution in future microphysics that would obligingly comply with his current philosophical specifications. And it may have occurred to Feyerabend that he might have to wait a very very long time, even assuming that future physics were ever to accommodate him at all. In any event he was led to reconsider quite radically his agenda for a realistic microphysics, and so instead of philosophizing to accommodate future physics to his Popperian universalist-realist agenda, he decided to philosophize to accommodate realism to the current quantum theory. Therefore he accepted Hanson’s conviction that any future microphysics will very likely contain duality.
But Feyerabend construed this to mean that duality must be expressed by complementarity, and in making his accommodation he did not ‘cut away’ the Bohr interpretation and proceed with a “liberalized” Copenhagen interpretation, as Hanson had advocated. Instead Feyerabend drew upon Bohr’s thesis of the relational nature of quantum states, which Feyerabend saw as contradicting universalist realism, and then generalized on Bohr’s relational thesis to affirm a nonuniversalist, relativized realism. Just as either the wave or particle manifestations of microphysical reality are conditioned upon respectively either one or another experimental arrangement, so more generally scientific knowledge is conditioned upon the historical situation and regional circumstances of the scientist. And even more generally all truth and knowledge including the particular Western tradition known as science, must be viewed in this historicist perspective.
It may be noted that Feyerabend had apparently been sympathetic to relativism even before his views on quantum theory had been influenced by Hanson. In 1962 he proposed his thesis of semantic incommensurability at the same time that Kuhn had used the same term to describe scientific revolutions. When critics pointed out the historical relativism implied in Kuhn’s use of the incommensurability thesis, Kuhn began to modify the concept so as to evade the relativistic implications. But Feyerabend made no such concession, when he defended use of the idea. In “Consolations for the Specialist” in Criticism and the Growth of Knowledge (1971) he defended the relativistic implications of Kuhn’s use of incommensurability, saying that the choice between incommensurable cosmologies is a matter of taste. In 1978 in his Science in a Free Society Feyerabend references Bohr’s relational interpretation of the quantum theory, which Bohr had devised in response to the criticism by Einstein, Podolsky and Rosen, as an example of an incommensurable theory relative to classical physics. In this context he says that the change from one world view described by a theory to another world view described by another theory that is incommensurable with the first, is a change in universal principles, such that one no longer speaks of an objective world that remains unaffected by one’s epistemic activities, except when moving within a particular world view. In this 1978 work Feyerabend continues to invoke universal principles. Bohr’s relational thesis is referenced merely as an example of incommensurability, and seems not yet to have become integral to Feyerabend’s cultural relativism.
But later in his “Introduction” to his Realism, Rationalism and Scientific Method (1981) Feyerabend states that quantum theory offers good reason to resist the universal application of his Thesis I and its realistic metaphysics. Logically to reject Thesis I is to reject common sense, and to announce that objectivity is a metaphysical mistake. But what physicists have actually done in effect is to reject the universal application of Thesis I, while still retaining in quantum theory some fundamental properties of common sense. In all but Bohm’s hidden-variables quantum theory, a universal realistic interpretation of the quantum theory has been replaced by a “partial instrumentalism”. Feyerabend explains that the transition to a partial instrumentalism contains two elements that are not always clearly separated.
The first element is the existence of multiple metaphysical traditions. One tradition usually associated with common-sense arguments in physics is the fact that there actually are relatively isolated objects in the world, and that physicists are capable of describing them. But there are also other metaphysical traditions, such as the Buddhist exercises, that create an experience, which neither distinguishes between subject and object nor recognizes distinct objects.
The second element in the transition to a partial instrumentalism is the choice by the physicist of one or another of these metaphysical traditions, and then the turning of the choice into a boundary condition for research. And this choice of metaphysical traditions, furthermore, is one between different sets of facts, because there are no tradition-independent facts.
He then states that the choice of metaphysical traditions is a choice among “forms of life”. Realism itself is thereby relativized to prior choices proceeding from cultural and social values. This is because a people decide to regard those things as real, which play an important rôle in the form of life they prefer. Thus the decision about what is real and what is not, begins with a choice of one or another form of life, and a people reject a universal criticism affirming a realistic interpretation of theories not in agreement with their chosen life form. Conversely realism merely reflects the preference for ideas accepted as foundational for their civilization and even for life itself. In this context instrumentalism is incidental to the choice of one or another theory for realistic interpretation. Instrumentalism is what is not culturally agreeable, and it no longer has the characteristics of a failure or defect. This resembles a thesis in sociology of knowledge in Peter Berger and Thomas Luckmann’s Social Construction of Reality (1966).
Feyerabend concludes that what has failed is not realism, but rationalism with its universalist criterion for realism. He welcomes the failure of rationalists to explain science in terms of tradition-independent standards and methodologies, because it is a failure to put an end to attempts to adapt science to chosen forms of life. The failure of rationalism has freed science from irrelevant restrictions. He adds that it is furthermore in agreement with the Aristotelian philosophy, which also limits science by reference to common sense, except that in Feyerabend’s philosophy the conceptions of the individual philosopher are replaced by the political decisions emerging from the institutions of a free society. This is Feyerabend’s thesis of “democratic relativism”.
His most mature and elaborate statement of his historicist and relativist philosophy is set forth in his Farewell to Reason (1987). In the “Introduction” to this book he writes that science has undermined the universal principles of research, and he asks rhetorically: who would have thought that the boundary between subject and object would be questioned as part of a scientific argument, and that science would be advanced thereby? And yet, as he notes in his next sentence, this is precisely what happened in the quantum theory. Feyerabend explicitly states that he does not deny that there are successful theories using abstract concepts. What he denies is that knowledge should be based on universal principles or theories. Echoing Conant, perhaps without even recognizing so, Feyerabend says that science is a living enterprise as opposed to a body of knowledge, and that it is an historical process, although unlike Conant, Feyerabend’s view is historicist and relativist, and also realist.
An important distinction that emerges from Feyerabend’s historical relativist philosophy is his distinction between “historical” or “empirical” traditions on the one hand and “theoretical” traditions on the other. This distinction is made in “Historical Background” in Problems of Empiricism and later in “Knowledge and the Rôle of Theories” and in “Trivializing Knowledge” in Farewell to Reason. His earlier philosophical views are clearly in the theoretical tradition, while his later views are clearly in the historical tradition. However, the distinction is not a fundamental one, because the thesis of his later view is that modern science with its theoretical tradition is a new historical tradition.
All theoretical traditions are really historical traditions according to Feyerabend’s later view. On the one hand the members of a theoretical tradition identify knowledge with universality, and they attempt to reason by means of a standardized logic. They distinguish the “real” world from the world of appearances, because they identify the reality with what their universal theories can describe as law-like and stable. And when their universal laws fail, the members of the theoretical tradition issue the “battle cry” stating: “we need a new theory!” In theoretical traditions true knowledge and logic are viewed as universal and independent of cultural traditions or regional circumstances.
On the other hand the members of an historical tradition emphasize what is particular including particular regularities such as Kepler’s laws. It produces knowledge that is restricted to certain regions, and which depends on conditions specifying the regions. And this knowledge is relative knowledge of what is true or false. Instead of using a standardized logic, they organize information by means of lists and stories, and they reason by example, by analogy and free association. They emphasize the plurality of knowledge, and consequently the history dependence and culture dependence of knowledge and of all logical standards. Feyerabend notes in this context that the complementarity thesis in modern quantum theory even contains the idea of relative knowledge, due to the relational character of quantum states.
In a discussion on the semantical interpretation of theories in his “Knowledge and the Rôle of Theories” Feyerabend bases his historical relativism on an artifactual theory of the semantics of language. He rejects the idea that there is any truth that is capable of superseding or transcending all traditions and cultures, an idea that he traces to Parmenides. He argues that this belief confounds the properties of ideas with their subject matter. The subject matter remains unaffected by human opinions, and the erroneous implication is that scientific statements describing the subject matter are supposed to be expressions of facts and laws, which exist and govern events no matter what anyone thinks of them. He maintains that the statements themselves are not independent of human thought and action; they are human products. They were formulated with great care to select only the “objective” ingredients of our environment, but they still reflect the peculiarities of the individuals, groups, and societies from which they arose. For example the validity of Maxwell’s equations is independent of what people think about electrification. But it is not independent of the culture that contains them; it needs a very special mental attitude inserted into a very special structure combined with quite idiosyncratic sequences of historical developments.
Theoretical traditions are opposed to historical traditions in intention, but not in fact. Scientists trying to create a knowledge that differs from “merely” historical or empirical knowledge, succeeded only in finding formulations which seemed to be objective, universal and logically rigorous, but which in fact are used and interpreted in use in a manner that conflicts with the properties the formulations only seem to have. Modern science is a new historical tradition that has been carried along by a false consciousness. Feyerabend similarly criticizes the metaphysics of scientific realism of the theoretical traditions of science. He construes scientific realism as accepting as real only what is lawful or may be connected by laws, and thereby regards the real to be what exists and develops independently of the thoughts and wishes of researchers.
Feyerabend argues that connecting reality with lawfulness is to define reality in a rather arbitrary manner. Moody gods, shy birds, and people who are easily bored would be unreal, while mass hallucinations and systemic errors would be real. The success of science cannot be a measure of the reality of its ingredients. He notes that to support their view, the scientific realists say that while scientific statements are the result of historical processes, the features of the world are independent of those processes. But he argues that we either consider quarks and gods to be equally real, or we cease to talk about real things altogether. And he adds that to say that quarks and gods are equally real is not to deny the effectiveness of science as a provider of technologies and of basic myths; he intends only to deny that scientific objects and they alone are real. And he adds that the equal reality of quarks and gods does not mean that we can do without the sciences; he acknowledges we cannot. Feyerabend’s equating scientific realism with scientism is to set up a straw man.
Feyerabend’s Criticism of Popper
Consider firstly Feyerabend’s general view toward Popper’s philosophy. Initially sympathetic to Popper’s philosophy, Feyerabend became one of its most relentless and truculent critics. In Against Method he rhetorically describes Popper’s views as “ratiomania” and “law-and-order science”. As his historical-relativist philosophy became more mature, Feyerabend described the technical procedures of Popper’s “critical rationalism” – the hypothesizing, testing, falsification, and new hypothesizing to produce new theories having greater empirical content – as merely rules of thumb, that cannot be taken as necessary conditions for science.
In opposition to Popper, Feyerabend takes sides with Kuhn by maintaining that science is an historical tradition having practices that are not always recognized as explicit rules, and that may change from one historical period to the next. He compares understanding a period in the history of science to understanding a stylistic period in the history of the arts. In both science and the arts periods have an obvious unity, but it is one that cannot be summarized in a few simple rules, and the practices that guide it must be found by detailed historical studies. The general notion of such a unity, which Kuhn calls a “paradigm” and which Lakatos calls a “research programme”, will therefore be poor in content. Feyerabend rejects the demands for precision made by some technical philosophers, saying that they are on the wrong track.
Consider secondly Feyerabend’s specific criticisms of Popper’s views on quantum theory. Feyerabend seems never to have been sympathetic to Popper’s propensity interpretation, which represents the participation by the philosopher in the work of the physicist. Even while he was sympathetic to Popper’s general philosophy, Feyerabend preferred to encourage physicists rather than to join them as Popper did. Later when Feyerabend reconciled himself to the Copenhagen interpretation, he became explicitly critical of Popper’s propensity interpretation. His criticisms of Popper are set forth in his “On A Critique of Complementarity” in Philosophy of Science (1968-1969), which he later had reprinted as “Niels Bohr’s World View” in Realism, Rationalism, and Scientific Method (1981). Popper had offered two interpretations of the statistical quantum theory during his career. The earlier interpretation offered in Logic of Scientific Discovery involved a variation on the frequency interpretation of probability, and the later interpretation first advanced in his “Quantum Mechanics without the Observer” (1967) was based on his propensity interpretation of probability. Feyerabend criticizes both these interpretations.
Feyerabend criticizes of Popper’s frequency interpretation of Born’s statistical quantum theory. He admits that it is not unreasonable, if physicists already know what kinds of entities are to be counted as the elements of the collectives, and if they know that those elements are classical entities. And he agrees with Popper that one cannot draw inferences about the individual properties of the elements. But Feyerabend argues that Popper’s view – that the elementary particle always posses a well defined value for all its magnitudes, i.e., position and momentum – is precisely what has been found to be inconsistent with the laws of interference and of the conservation laws. He therefore maintains that a new interpretation of the elements of quantum-mechanical collectives is needed, and that what is being counted as elements is not the number of systems possessing a certain well defined property. Rather what is counted is the number of transitions from certain partly ill defined states into other partly ill defined states, as Bohr had maintained.
Feyerabend’s criticizes of Popper’s propensity interpretation. Popper viewed probability as a propensity, a physical property comparable to physical forces and pertaining to a whole experimental arrangement for repeatable measurements. The wave function determines the propensity of the states of the particle, in the sense that it gives weights to its possible states. Thus in the two-slit experiment a change in the experimental arrangement such as shutting one of the slits, affects the distribution of the weights for the various possibilities, and thus produces a different wave function. Such a change in the experimental arrangement is analogous to tilting a pin board with the result that a new distribution curve of the rolling balls will differ from the distribution prior to the tilting of the pin board. Popper therefore views quantum mechanics as a generalization of classical statistical mechanics of particles together with the propensity interpretation of probability. Feyerabend says that Popper’s propensity interpretation is much more similar to Bohr’s view, which Popper attacks, than to Einstein’s view, which Popper attempts to defend. He says Popper’s thesis that the experimental conditions of the whole physical setup determine the probability distribution is precisely Bohr’s relational thesis, when Bohr proposed defining the term “phenomenon” to include the whole experimental arrangement.
But Feyerabend’s thesis is furthermore that Bohr’s idea of complementarity goes beyond the propensity interpretation by attributing to the experimental arrangement not only probability but also the dynamical variables of the physical system, notably position and momentum. Therefore Popper’s thesis that a change in experimental conditions implies a change in probabilities alone is not adequate to account for the kind of changes involved in the two-slit experiment. In other words complementarity asserts the relational character not only of probability, but also of all dynamical magnitudes. Feyerabend agrees with Popper that a change of experimental conditions changes probabilities, but he also says that what led to the Copenhagen interpretation is not merely the fact that there is some change in distribution with a change of experimental arrangement, but also the kind of change encountered: trajectories which from a classical view are perfectly feasible, are forbidden to the particle.
This is because the conservation laws apply not only on the average, so that one could postulate a redistribution without asking for some dynamical cause, but furthermore they apply in each single interaction. Thus a purely statistical redistribution is inadequate; each single change of path must be accounted for. Bohr’s resolution consists of the renunciation of particle trajectories, the denial that particles possess well defined position with well defined momenta according to the indeterminacy relations. Feyerabend maintains that Popper confused classical waves with quantum waves, because he neglected the dynamics of the individual particle and construed quantum theory as pure statistics. Popper’s claim that the reduction of the wave packet is not an effect characteristic of quantum theory, but rather is an effect of probability in general, and that Popper’s claim is incorrect in Feyerabend’s view. And Popper’s claim that duality is the “great quantum muddle” is in Feyerabend’s words nothing but a piece of fiction.
Feyerabend also has a number of other specific criticisms of Popper’s philosophy of science, which are summarized in “Historical Background” in Problems of Empiricism, the second volume of Feyerabend’s collected papers. There are eight such specific criticisms, which may be summarized as follows:
1. Feyerabend notes that theory exchange has not always proceeded by falsification. Noteworthy examples include the transition from the celestial theory of Ptolemy and Aristotle to that of Copernicus, and the transition from Lorentz’s theory to Einstein’s theory of special relativity. In these cases there were no refuting facts to explain rejection of the preceding theory.
2. The meaning of a hypothesis often becomes clear only after the process that led to its elimination has been completed. The force of this objection seems to be that falsification brings about meaning change, that the decision to accept a test outcome as a falsification is also a decision that affects the semantics of the language involved in the test. Feyerabend elaborates on this thesis in his “Trivializing Knowledge” in Farewell to Reason, a paper criticizing Popper’s philosophy. In this paper Feyerabend says that the content of theories and experiment are constituted by the refutations performed and accepted by the scientific community, rather than being the basis on which falsifiability can be decided and refutation determined. He exemplifies this point with the stereotypic theory “every raven is black”, and he says that while a white raven falsifies this theory, the refutation depends on the reason for whiteness. A decision must be made as to whether a raven whose metabolic processes make it white, or whose genetic make up has been altered to make it white, or which has been dyed white, constitutes a falsifying instance. Feyerabend says that such decisions are not independent of falsification. He also uses this example to illustrate Lakatos’ philosophy of science in “Popper’s Objective Knowledge” a critical review of Popper’s book in Problems of Empiricism. Here he states that what is needed is some insight into the causal mechanism that brought about whiteness, a theory of color production in animals. He also notes that this illustration shows the need for alternative theories in the process of testing.
3. The transition to a new theory may involve a change of universal principles, which breaks the logical links between the theory and the content of its predecessor. This break produces the semantic incommensurability that Feyerabend discussed at length in Against Method and in earlier papers. Incommensurability is not only the principal basis for his historical relativism, which Popper opposes, but is also inconsistent with Popper’s thesis of scientific progress through increasing empirical content and verisimilitude.
4. Feyerabend rejects Popper’s thesis of increasing content for reasons in addition to the occurrence of semantic incommensurability. This is a criticism that Feyerabend discusses at length in Against Method, where he states that a new period in the history of science commences with a “backwards movement” to a theory with less empirical content, that gives scientists the time and freedom needed for developing the main thesis of the new theory in greater detail, and also for developing related auxiliary sciences. Scientists are persuaded to follow this backward movement by such “irrational” means as propaganda and ad hoc theories that sustain a blind faith in the new theory until it turns into what comes to be regarded as sound knowledge. This is what Feyerabend saw in Galileo’s defense of the Copernican theory, where the relevant auxiliary science needing further development at the time was optics.
5. A closely related criticism of Popper’s philosophy is Feyerabend’s thesis that ad hoc adaptation of a theory may be the right step to take. The ad hoc adaptation may be made either to the theory or to the statements of observation. In Popper’s philosophy these ad hoc adaptations are objectionable as content-decreasing stratagems. But Feyerabend maintains that they disguise the inadequacy of a new theory until the relevant auxiliary sciences can be developed, so that refutation ultimately might not occur.
6. The demand that the scientist look for refutations and take them seriously, will lead to an orderly development only in a world in which refuting instances are rare and turn up at large intervals. But this is impossible since an ocean of anomalies surrounds theories, unless we modify the stern rules of falsification using them only as rules of thumb, and not as necessary conditions for scientific procedure. Feyerabend frequently states elsewhere in his literary corpus that strict falsification would wipe out science as it presently exists, and would never permit it to have come into existence.
7. Popper’s demand for increasing content makes sense only in a world that is infinite both quantitatively and qualitatively. On the other hand in a finite world containing a finite number of basic qualities or elements, the aim is firstly to find these elements, and then secondly to show how novel facts can be reduced to them with the help of ad hoc hypotheses. He adds that genuine novelty counts as an argument against the methods that produce it. Feyerabend gives no further explanation of what he means by this peculiar criticism, nor does he give any reference to any other part of his corpus for explanation.
8. Finally Feyerabend objects that content increase and the realistic interpretation of the idea that brings it about, restrain human freedom.