paradigms
Thomas Kuhn's Paradigms
30/05/09 18:45
Kuhn’s thesis is that scientific progress does not proceed cumulatively, as most people have believed. Instead, he says that it oscillates between stable periods of “normal science,” during which scientists elaborate and extend a single dominant paradigm, and revolutionary breaks, when an existing paradigm is abandoned in favor of a new one.
Kuhn rejects the belief that knowledge progresses by a series of “successive increments” (p. 2) which add to the accumulation of facts making up current scientific truth. He disputes the description of professional scientific life as an impartial empirical exploration, describing it instead as being guided and directed by paradigms which create the rules and standards for a scientific community. Sharing a paradigm allows this community to take the foundations of their field for granted, resulting in highly refined studies into the most esoteric and elaborate problems.
Kuhn describes “normal science” as “mop-up work,” which he describes as “an attempt to force nature into the preformed and relatively inflexible box that the paradigm supplies.” (p. 24) The “normal” scientist is “an expert puzzle-solver,” (p. 36), and the mark of a puzzle is the certainty of a single correct solution. This does not mean there is a single right solution in nature, just in the paradigm.
Anomalies between observations and paradigm-induced expectations are the first clues to the weakness of a particular paradigm. Kuhn says the difficulty of seeing anomalies is due to the conditioning of our expectations by the paradigm. Normal science produces sufficiently detailed information and exact enough expectations that discovery of anomalies is enabled. Insecurity caused by a growing preponderance of anomalies leads to a crisis for the existing paradigm. “Failure of existing rules is the prelude to a search for new ones.” (68)
The response to a crisis is not immediate abandonment of the paradigm. Falsifiability in Popper’s sense does not play a role; a paradigm is never released until a new one is accepted in its place. “Every problem that normal science sees as a puzzle can be seen, from another viewpoint, as a counterinstance,” (79), but some of these can ultimately be answered within the existing paradigm. Others point the way to new paradigms. “Almost always the men who achieve these fundamental inventions of a new paradigm have been either very young or very new to the field whose paradigm they change.” (90)(What are the implications for highly professionalized disciplines like history?)
Revolutions result when a scientific community rejects an existing paradigm in favor of a new one. There may have been several contenders, but only one paradigm can win without splitting the field into separate disciplines. The new paradigm comes to be recognized as better than the old one based on the set of criteria which (now) matter to the community. The relative importance of these criteria may vary between individuals and over time. But the result of accepting the new model is recognition of the failure of the old.
Adoption of the new paradigm changes the scientist’s perceptions, tools, and language in a way that makes his understanding incommensurable with that of the old-paradigm scientists. “Confronting the same constellation of objects as before and knowing that he does so, he nevertheless finds them transformed.” (122) Ultimately all experience is processed through interpretive structures (paradigms), so there is no “neutral observation-language” from which to judge the paradigms. The process works like a “gestalt-switch,” Kuhn says.
Scientific revolutions appear invisible because that is not the way we learn science. Paradigm choices are made, not based on “comparison of a single paradigm with nature,” (145) because nature cannot be SEEN except through a paradigm. The paradigm cannot be accepted incrementally, it must be experienced. This is why there is no going back. It is not always clear that the new paradigm is more successful than its predecessor when the decision is made. There is an element of faith involved.
This model works in science because of its reliance on a single paradigm at a time, and its very detailed elaboration of that paradigm. There is an “evolutionary” element to the revolutions, in that the new paradigm must solve the outstanding counterinstances which caused the crisis (at least better than the old paradigm did), AND it must “promise to preserve a relatively large part of the concrete problem-solving ability” of the predecessor model. But there is NO implied evolution TOWARD any goal or truth, just a “process of evolution from primitive beginnings.” (170)
In the Postscript, Kuhn REALLY improves on the clarity and complexity of the argument.
The term Paradigm is refined to mean: “the entire constellation of beliefs, values, techniques, and so on shared by members of a given community,” AND “the concrete puzzle-solutions which, employed as models or examples, can replace explicit rules as a basis for the solution” of scientific questions. (175) “A paradigm governs…not a subject matter but a group of practitioners.” (180)
“Crises need not be generated by the work of the community that experiences them and that sometimes undergoes revolution as a result,” Kuhn says. (181)
Kuhn elaborates a very detailed argument of how paradigms relate to human knowledge. This involves a “disciplinary matrix” which holds a group of sciences together and defines a “field” of science (182), “symbolic generalizations” which “look like laws of nature,” and are also definitions of the symbols (“the balance between their inseparable legislative and definitional force shifts over time” as the paradigm matures) (183). There are overarching “metaphysical paradigms”: “beliefs in particular models…[that] supply the group with preferred or permissible analogies and metaphors” (184), “values” such as plausibility, consistency, mathematical beauty, etc. Their relative hierarchy changes between scientists and over time. Because these are communities of teachers and students, the paradigm includes “exemplars” or “concrete problem-solutions that students encounter.” The “differences between sets of exemplars provide the community fine-structure of science,” and because they point directly to the way humans know anything, learning a particular set means a student has “assimilated a time-tested and group-licensed way of seeing.” (189)
In his discussion of knowledge, Kuhn says we are “tempted to identify stimuli one-to-one with sensations,” and that we “posit the existence of stimuli to explain our perceptions of the world, and we posit their immutability to avoid both individual and social solipsism.” (193) He says that paradigms, in their role as exemplars, allow us to “learn to see the same things when confronted with the same stimuli.” (193) This creates the unity of the scientific discipline (other disciplines might ask themselves if they can be this monolithic?)
“An appropriately programmed perceptual mechanism has survival value,” Kuhn says. “To say that the members of different groups have different perceptions when confronted with the same stimuli is not to imply that they may have just any perceptions at all.” (195) “What is built into the neural process that transforms stimuli to sensations has the following characteristics: it has been transmitted through education; it has, by trial, been found more effective than its historical competitors in a group’s current environment; and, finally, it is subject to change both through further education and through the discovery of misfits with the environment.” Because this is an embedded, invisible process, he calls this layer “tacit knowledge.” (196) This is the evolutionary psychology that links David Hume with the real world.
Kuhn continues: “interpretation begins where perception ends. The two processes are not the same, and what perception leaves for interpretation to complete depends drastically on the nature and amount of prior experience and training.” (198) This is a hidden element of paradigm use, which is not under conscious control. “There is no neutral algorithm for theory-choice, no systematic decision procedure which, properly applied, must lead each individual in the group to the same decision… Two men who perceive the same situation differently but nevertheless employ the same vocabulary in its discussion must be using words differently.” (200) So they need TRANSLATION. But: “To translate a theory or worldview into one’s own language is not to make it one’s own. For that one must go native, discover that one is thinking and working in, not simply translating out of, a language that was previously foreign.” (204) This is the CONVERSION EXPERIENCE, and Kuhn says it is necessarily one-way. “Translation may… provide points of entry for the neural reprogramming that, however inscrutable at this time, must underlie conversion. But neither good reasons nor translation constitute conversion…” (204) You know it when it happens.
Does it work this way in the social sciences? Kuhn seems to be proposing this as a theory of all human knowledge. The “notion of a paradigm as a concrete achievement, an exemplar” (208) gets past a lot of arguments about subjectivity, facts, and language. But “How does one elect, and how is one elected to membership in a particular community, scientific or not? What is the process and what are the stages of socialization to the group? What does the group collectively see as its goals; what deviations, individual or collective, will it tolerate; and how does it control the impermissible aberration?” (209) These are BIG questions for me thinking about the academic discipline of history right now.
