Scientific Revolutions—“non-cumulative developmental episodes in which an
older paradigm is replaced in whole or in part by an incompatible
new one” (p. 92)
· Scientific revolutions are “inaugurated by a growing sense, . . . often restricted to a narrow subdivision of the scientific community, that an existing paradigm has ceased to function adequately in the exploration of an aspect of nature to which that paradigm itself had previously led the way.” (p. 92)
· Choices among competing paradigms cannot be made on the basis of the “evaluative procedures” of normal science because those procedures are parts of the competing paradigms and are therefore at issue. (p. 94)
· Therefore, in the debates about choice of paradigms the arguments that are based on those paradigms are necessarily circular and therefore are not logically or probabilistically compelling. However, this does not mean that such arguments cannot be persuasive or persuasive.
· “. . . [T]here is no standard higher than the assent of the relevant [scientific] community.” (p. 94)
· In principle, the discovery of new phenomena does not necessitate abandoning the current paradigm. (p. 95)
· However, historically, except for pre-paradigm periods, assimilation of new theories and phenomena almost always involves destruction of the previous and competition among “schools of scientific thought.” (p. 96)
· New discoveries can occur only if scientists’ expectations about nature and/or their instruments (laboratory, measuring, etc.) turn out to be wrong. (p. 97)
· Assimilating anomalies as instances of scientific laws almost always requires that a new paradigm be adopted and that the old paradigm be destroyed. (p. 97)
· New theories are invented to resolve anomalies with respect to the current theory. Since a new theory can resolve such anomalies only if it is logically incompatible with the current theory, it must supplant the current theory. Consequently, a new paradigm, of which the new theory is a part, must replace the current paradigm.
· According to a view associated with logical positivism,
o The range of application of a scientific theory does not extend beyond the phenomena and observational precision already dealt with by the existing experimental evidence.
o Therefore, one theory does not conflict with another theory if the two theories do not make conflicting predictions.
o In particular, a more extensive theory (e.g., Einstein’s theory of relativity) does not conflict with a less extensive “special case” theory (e.g., Newtonian dynamics) as long as the predictions of the latter are among those of the former. (p. 98)
· The logical positivist view has the following implications:
1. Every significant scientific theory is immune to attack, since it predicts nothing about “new phenomena.” (pp. 99-100)
2. Scientific theories cannot guide research, since they are not to be “tested” by checking to see if their predictions of “new phenomena” are correct. (p. 100)
3. There can be no “surprises, anomalies, or crises” with respect to an existing theory. (pp. 100-101)
4. Therefore, there can be no extraordinary science, which leads to the advances associated with scientific revolutions. (pp. 100-101)
· The positivist argument that Newtonian dynamics is a “special case” of relativistic dynamics, which is based on deriving Newtonian equations as limiting cases of relativistic equations where v/c<<1, is flawed because it assumes that the meanings of important terms in both theories (e.g., “mass”) are the same. However, the meanings are not the same. (pp. 101-102)
· Successive paradigms in an area of science (e.g., Newtonian and relativistic dynamics) differ in the following respects:
1. They have different implications about what entities the universe contains and how those entities behave. (p. 103)
2. They differ with respect to what methods, problems, and standards of solution are accepted by the scientific community. (p. 103)
3. They differ with respect to what qualifies as “scientific” and what is rejected as “unscientific.” (p. 103)
· When a scientific revolution occurs, the normal science tradition that emerges is incommensurable with the old normal science tradition. (p. 103)
· Examples of differences among competing paradigms with respect to accepted entities, significant problems, and legitimate solutions include the following:
1. the legitimacy of referring to “occult qualities” (pp. 104-105)
2. whether “explaining gravity” is a significant scientific problem (p. 105)
3. whether there are such things as “innate forces”—gravitational, electromagnetic, chemical affinities, etc. (pp. 105-107)
· The standards determining what problems are significant and what solutions are legitimate are internal to paradigms. There is no standpoint external to competing paradigms from which to judge those standards. Therefore, those standards may change but they do not become “higher” or “lower.” (p. 108)
· Disagreements among the supporters of competing paradigms about which unsolved problems are more important than others raise value issues that cannot be resolved within normal science. (p. 110)