(D) Taxonomy of Views on the Nature of Science
In order to bring into sharper focus the similarities and differences of the major positions on the nature of science discussed in this work, I would like presently to turn to the problem of taxonomy of these positions. Attempts at a careful classification of the positions discussed will also bring out the areas of ambiguity implicit in the above positions and thus point out the questions that need to be further commented on by the defenders of the respective positions. Furthermore, such a classification will bring into sharper focus the position that I am propounding in contradistinction to such men as Kuhn and Feyerabend. The modus operandi of the classification will be to list sets of ingredients which best represent the respective positions discussed.
a. Inductivist Position.
The inductivist position can be described by the following ingredients: 1. The beginnings of science, more appropriately called pre-science, can be characterized by a plurality of theories about nature. Schematically, it can be said that these theories were T1, T2, T3, . . ., Tn. I will call this stage of pre- science "Theoretical Pluralism." 2. The early existence of a plurality of theories can be accounted for by the fact that scientists did not follow the inductive method as described by Francis Bacon. Only after scientists had divested themselves from all theoretical prejudices did it become possible to begin true scientific research. Such research must begin with the collection of facts, classification of these same facts, and then by the method of induction arrive at the one true theory. The rest of science can be characterized by a linear progress towards the true theory. With the development of science, theories of narrow scope become subsumed under more general theories. There are no revolutions in science. Science is a cumulative activity on theoretical as well as factual levels.
b. Feyerabend's Theoretical Pluralism.
Feyerabend's T.P. can be characterized by the following stages: F1. Science in its beginnings, as well as throughout its develop mental history, can be and ought to be characterized by the existence of a plurality of mutually incompatible and factually adequate theories. Scientists must have at all times as their objective the creation of such a plurality of theories. This view of science has been appropriately called the philosophy of Theoretical Pluralism. F2. When the creation of alternative theories stops and scientists become content for a long period of time with some other theory, this should be viewed with alarm. Too long a preoccupation with one theory leads to stagnation and is a sign that the creative activity of scientists has come to an end. The philosophy of theoretical pluralism must be in effect at all times. For no one theory can adequately describe all of nature. Man is in principle incapable of creating one theory which will adequately capture all of the varieties of nature. There is some doubt as to whether Feyerabend believes that a science must have periods of normal science (i.e., a field in science is dominated by one theory). In the following passage he seems to subscribe to short periods of normal science.
Indeed, any consistency over a long period of time would have to be regarded not as suggested by (3) (A) and (5), as a methodological virtue but as an alarming sign that no new ideas are being produced and that the activity of theorizing has come to an end. Only the inductivist doctrine that theories are uniquely determined by the facts would have persuaded people that lack of ideas is praiseworthy and that its consequences are an essential feature of the development of our knowledge.{45} As he says here, monism seems to be fine provided that it doesn't last for a long time.
There are times when Feyerabend speaks of some one theory being victorious for a time, suggesting a period analogous to the normal science stage. There seems, however, to be a need for the following modification in our description. During the period of normal science the theories that lost the fight must be kept alive to serve as perpetual reminders that the winner is still superior. Furthermore, scientists must develop new alternative theories always for the sole purpose of boosting the position of the up-to-now-superior-theory. Should a better theory be created, or the old one falsified, the new one takes over as the dominant theory. The following passage supports such a view.
The principle of proliferation not only recommends invention of new alternatives, it also prevents the elimination of older theories which have been refuted. The reason is that such theories contribute to the content of their victorious rivals. Thus, certain contemporary attempts to give a classics account of typically relativistic effects provide further tests for relativity, and their failure further corroborating evidence. . . . Knowledge so conceived is not a process that converges towards an ideal view; it is an ever increasing ocean of alternatives, each of them forcing the others into greater articulation; all of them contributing via this process to the development of our mental faculties.{46} In the above passage he speaks of "victorious rivals," suggesting that some theories win out and become the dominant theory. This clearly points in the direction of normal science in the modified sense given above. The following passage also seems to indicate that he holds that there are periods when one theory is dominant.
Invent and elaborate theories which are inconsistent with the accepted point of view even if the latter should happen to be highly confirmed and generally accepted.{47} Furthermore, Feyerabend speaks of certain theories as forming the "scientific ideologies" of the time. This again suggests that some one theory seems to be dominant for a time, again suggesting a period of normal science. In view of these considerations, I am inclined to include a period of "normal" science in the modified sense, as part of Feyerabend's Philosophy of Theoretical Pluralism.
c. Thomas Kuhn -- Revolutions Forever or Revolutions in the Past?
The following are the ingredients of what I take to be Kuhn's theory of scientific development. K1. The beginnings of a science, or more appropriately, the prescience stage has usually been characterized by a plurality of theories. Schematically, it can be said that these theories were T1, T2, T4, . . ., Tn. This pre-science state I will call "Theoretical Pluralism Stage." K2. The period of theoretical pluralism comes to an end with the selection of one theory from among the competing ones. Let us assume for the purpose of better explication that T1 was selected. It should be pointed out that this T1 need not be a fully developed or an axiomatized theory. It could contain just the kernel of a theory, such as some principle which scientists find worthwhile developing, or a particular solution to some problem that sparks the scientists' imagination, etc. There follows a period of science which consists in development of T1 on various levels: (a) theoretical articulation of the theory, such as resolving of ambiguities, finding of acceptable definitions of key terms; (b) determination of relevant "facts" with greater precision, and so on. During this period science is a cumulative enterprise. Kuhn has called such a period of scientific activity normal science. K3. Our study of the history of science reveals that a period of normal science has usually been succeeded by a crisis stage. It is believed that such crises are precipitated by anomalies, i.e., certain problems and puzzles deemed important by T1 are recalcitrant to solution by the methods of T1 even after repeated attempts to remove them by the best scientific minds of the time. During such periods, scientists must return to the methodology of the Theoretical Pluralism Stage in science and invent alternatives to T1 which can remove the anomalies by finding a solution to the problem or problems which were responsible for leading T1 into crisis. Such a crisis stage comes to an end when the scientific community decides on a theory which resolves those problems that led the old paradigm theory into crisis. The final effect of such a change is a revolution because the old theory is no longer held in repute. Scientists still practicing science under the old theory are sometimes called crack-pots or people engaged in pseudo-science. The period in science which begins with the discovery of anomalies and ends with the revolutionary overthrow of the old theory is in a state of crisis and is dominated by the Philosophy of Theoretical Pluralism. Thus far, Kuhn's position is clear and without ambiguity. But I come now to an important question, the answer to which I have difficulty finding in Kuhn's writings. Does Kuhn claim that scientific revolutions will continue indefinitely or does he claim only that these revolutions have occurred in the past but that they need not occur in the future. We have to decide between the following two descriptions of scientific development. K4. The process of going from the first stage of Theoretical Pluralism to the stage of Normal Science and then because of crisis back to Theoretical Pluralism correctly describes not only the history of past scientific theories, but also the future history of scientific theories. Such a process must continue indefinitely without ever ending at the Normal Science stage because man is incapable of creating a theory that can ever adequately capture the great variety of nature. K5. The process of Theoretical Pluralism, Normal Science, and, due to crisis, back to Theoretical Pluralism, correctly describes the history of past sciences but it need not continue thus into the future. It is in principle possible that in some fields of science such a process comes to an end at the second stage. The problem is whether such a developmental process of normal science followed by theoretical pluralism must continue indefinitely into the future (ingredient 4), or can it ever stop at the normal science stage (ingredient 5)? There appears to be no easy answer in SSR. On the one hand, Kuhn has tried to supply us with a picture of how science works and so one would think that it applied as well concerning the future development of science. On the other hand, one can argue that Kuhn, being primarily a historian of science, has tried to provide us with a picture of the structure of scientific revolutions, but only in the past. Since Kuhn is still very much alive, this certainly is an important question that needs to be resolved about his thought.
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Notes
{45} E.R.E., p. 50. [Back]
{46} "Comments", p. 225. [Back]
{47} Ibid., p. 224. [Back]
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