In the last installment of this series, we reviewed the position of one of the 20th century’s greatest philosophers of science, Karl Popper. The latter took issue with logical positivism, the prevailing philosophy of science during his intellectually formative years, a philosophy which maintained that scientific statements were statements whose truth could be verified through experience. Truth couldn’t be proven, Popper insisted. Rather, scientists strive to refute their own theories. So, what makes a theory scientific is that it can be falsified.
Thomas Kuhn, a physicist by training, became every bit as prominent the philosopher as science as Popper. In fact, inasmuch as his The Structure of Scientific Revolutions has become one of the most widely cited academic books of all time (and the most widely cited book in the social sciences) since its publication in 1962, it’s a safe bet to say that Kuhn is even more influential than the Austrian thinker whose work he critiqued.
Kuhn contended that analysis of the history of science disclosed that neither Popper’s nor the logical positivists’ conception of science aligns with what scientists actually do. Science does not consist of a progressively growing body of objective truths to which each new generation adds, as the positivist’s more traditional account would have us think. Yet neither do scientists regard the first anomalous occurrence of which they become aware as a decisive refutation of their theories, as Popper argued.
Rather, scientists operate within a “disciplinary matrix,” or a “paradigm.”
A paradigm is the conceptual lens through which the members of a scientific community view their work. It consists, fundamentally, of “the operations and measurements that a scientist undertakes in the laboratory [.]” These, in other words, “are not ‘the given’ of experience [.]” They are “concrete indices to the content of more elementary perceptions” that, as such, are noticed by the scientist, if at all, only after “his research is well advanced and his attention focused.”
Laboratory operations and measurements, then, are, significantly, “paradigm-determined.” They are favored because “they promise opportunity for the fruitful elaboration of an accepted paradigm.”
Moreover, the “immediate experience” of the subscribers to a particular paradigm, i.e. what they see, is, at least partially, “determined” by that paradigm.
Since, then, science “does not deal in all possible laboratory manipulations,” this means that “scientists with different paradigms engage in different concrete laboratory manipulations” (emphases added).
Paradigms, Kuhn further claims, are “incommensurable.” There’s been much written on this notion of incommensurability. What Kuhn seems to be saying is that the terms of one paradigm aren’t readily translatable into those of another. This being the case, no one paradigm can ever be judged to be superior or inferior to another, at least not with respect to any paradigm-neutral or objective standards of evaluation, for there are none.
The implications of this are clear: Scientific progress is not and never has been the linear phenomenon that it is made out to be. Rather, it consists of “paradigm shifts.” Kuhn delineates four stages of scientific development:
First, there’s “pre-science,” or the pre-paradigm phase. Not a whole lot is happening here, for the paradigm has not yet taken hold.
Second, once the paradigm solidifies—once there is consensus among the members of the scientific community as to the assumptions, the central theories, values, instruments, and, yes, metaphysical commitment(s) that constitute the paradigm—then “normal science” occurs. When scientists practice normal science, they draw upon the conceptual resources of the paradigm to both identify and resolve problems or “puzzles.”
Third, anomalies—problems or outcomes for which the paradigm appears to be unable to account—occur even during normal science, but as long as they aren’t disruptive or regarded as terribly significant, the paradigm remains settled and normal science continues. However, when a particularly burdensome problem or set of problems arise, the paradigm suffers “crisis.”
The crisis owes to the fact that the paradigm, as is, has proven itself incapable of resolving these anomalies.
Fourth, crisis leads to “revolution.” The paradigm is dramatically revised so as to resolve the problems that gave rise to the crisis.
And if the crisis is sufficiently grave, it could eventuate in the abandonment of the paradigm itself and a “shift” to another.
Kuhn explains that crisis is a stage consisting of “a proliferation of compelling articulations, the willingness to try anything, the expression of explicit discontent, the recourse to philosophy and to debate over fundamentals.”
Scientists, in other words, operate within intellectual frameworks or traditions that determine what they perceive and how they perceive it. Aristotle, for example, is among those whose analyzes Kuhn extols as exemplary instances of good science (Ptolemy, Newton, Lavoisier, and Maxwell are some others). By contemporary standards—the standards of the paradigm(s) that we endorse—Aristotle can’t sound more inaccurate. Yet this is precisely the point: We are judging him in light of the standards of a paradigm that is incommensurable with the one that he advanced. Kuhn writes:
“The question I hoped to answer was how much mechanics Aristotle had known, how much he left for people such as Galileo and Newton to discover. Given that formulation, I rapidly discovered that Aristotle had known almost no mechanics at all [.]”
This bothered Kuhn, for “Aristotle appeared not only ignorant of mechanics, but a dreadfully bad physical scientist as well. About motion, in particular, his writings seemed to me full of egregious errors, both of logic and of observation.”
While recounting his initial impression of Aristotle, Kuhn then recalled the place and time when it dawned upon him that he had been mistaken and that Aristotle had indeed “made sense” after all. Aristotle, he realized, labored within a paradigm that wasn’t inferior to, but merely different from, that upon which Newton’s inquiries depended. While Newton and modern peoples generally think of “motion” exclusively in terms of locomotion, of a change in location, Aristotle treated the term synonymously with any and all change. Given his understanding of motion, then, the conclusions that he drew from it were intelligible and his science coherent.
So, to be clear, for all of their differences, both the logical positivists’ and Popper’s conceptions of science are mistaken. Whether we insist, as the positivists insisted, that science is distinguished on account of its ability to verify the truth of its theories, or whether we concur with Popper that it is its falsifiability that differentiates science from other modes of cognition, both views presuppose that there is an absolute standard of evidence by which theories live or die. All observations and evidence, though, are paradigm-based.
It should be noted that the ghost of Kant, at whose epistemology we looked at an earlier installment of this series, is resurrected in Kuhn—but with a twist! Kant, remember, thought that the human mind is itself a paradigm, a set of “categories” and “pure intuitions” that it imposes upon the raw inputs of the senses. The only world that the mind ever knows, then, is the mind that it constructs via the conceptual lens of the human mind.
Yet Kant believed that this paradigm was one and the same for all humans. Kuhn, as we now know, thought that there are many paradigms and that they are all historically and culturally-specifically.
The point, though, is that scientists never see the world as it is. The world, or the aspects of it that scientists select for study, is a world that is filtered through whatever paradigm it is to which its adherents agree.
Given Kuhn’s reading of the matter, it becomes clear that the history of science, of how science is actually done, has much more to do with politics and peer pressure than the popular, traditional, “heroic” conception of science would have us believe. Scientists are initiated, more or less subconsciously, into communities of other scientists. They subconsciously sign onto the consensus, the paradigm, that already exists and within which normal science is being practiced. There can’t be any scientific inquiry independently of the paradigm.
Kuhn is clear that science and philosophy of science are inextricable from one another. All science embodies some philosophy of science. This conviction on his part is especially provocative in light of the COVID era. Kuhn died in 1996, but the remark that he made during an interview with Scientific American regarding HIV/AIDS has implications for the prevailing narrative on SARS CoV-2/COVID 19. The interviewer, John Horgan, asserted that “the hypothesis that AIDS is caused by the human immunodeficiency virus is either right or wrong,” and that “metaphysics and language,” i.e. philosophy, are “beside the point.” Years later, he recounted Kuhn’s response: “Whenever you get two people interpreting the same data in different ways, that’s metaphysics.”
Kuhn’s analysis generated no small supply of commentary, both favorable and critical. In the next essay, we’ll look at Paul Feyerabend whose philosophy of science was far more radical than that of Kuhn’s.