Last time, we discussed Laudan's reticulationist model of scientific justification. In this session, we will examine Laudan's arguments for thinking that his model does better than Kuhn's quasi-hierarchical, "holist" model at explaining both how agreement and disagreement emerges during scientific revolutions. As you recall, Laudan argues that what change in the aims or goals of a scientific discipline can result from reasoned argument if there is agreement at the methodological and/or theoretical (factual) level. In other words, if any of the three elements in the triad of theories, methods, and aims is held fixed, this is sufficient to provide reasonable grounds for criticizing the other elements. Laudan's view is "coherentist," in that he claims that scientific rationality consists in maintaining coherence or harmony between the elements of the triad.
This picture of reasoned argument in science requires that the aims-methods-theories triad be separable, i.e., that these elements do not combine to form an "inextricable" whole, or Gestalt, as Kuhn sometimes claimed. If some of these elements can change while the others are held fixed, and reasoned debate is possible as long one or more of the elements are held fixed, then this leaves open this possibility that scientific debates during what Kuhn calls "paradigm change" can be rational, allowing (at least sometimes) for relatively quick consensus in the scientific community. This could occur if scientific change were "piecemeal," i.e., if change occurred in only some elements of the aims-methods-theories triad at a time. Indeed, Laudan wants to argue that when examined closely scientific revolutions are typically piecemeal and gradual rather than sudden, all-or-nothing Gestalt switches. The fact that it often looks sudden in retrospect is an illusion accounted for by the fact that looking back often telescopes the fine-grained structure of the changes.
Kuhn on the Units of Scientific Change
For Kuhn, the elements of the aims-methods-theories triad typically change simultaneously rather than sequentially during scientific revolutions. For example, he says: "In learning a paradigm the scientist acquires theory, methods, and standards together, usually in an inextricable mix." In later chapters of SSR, Kuhn likens paradigm change to all-or-nothing Gestalt switches and religious conversion. If this were so, it would not be surprising if paradigm debate were always inconclusive and could never completely be brought to closure by rational means. Closure must then always be ultimately explained by non-rational factors, such as the (contingent) power dynamics within a scientific community. As Laudan argued in Chapter 1 of SV, factors such as these cannot fully explain why it is that closure is usually achieved in science whereas it is typically not in religions or other ideologies, or why it is that closure is normally achieved relatively quickly.
Laudan's solution to the problem of explaining both agreement and disagreement during scientific revolutions is not to reject Kuhn's view entirely, but to modify it in two ways.
Question: How could piecemeal change occur? Laudan first sketches an idealized account of such change, and then attempts to argue that this idealized account approximates what often happens historically. (Go through some examples of the former in terms of a hypothetical "unitraditional" paradigm shift.) The fact that it does not look like that in retrospect is normally due to the fact that history "telescopes" change, so that a decade-long period of piecemeal change is characterized only in terms of its beginning and end-points, which exhibits a complete replacement of one triad by another. "...a sequence of belief changes which, described at the microlevel, appears to be a perfectly reasonable and rational sequence of events may appear, when represented in broad brushstrokes that drastically compress the temporal dimension, as a fundamental and unintelligible change of world view" (78).
(Now go through what might happen if there are different, competing paradigms.) When there is more than one paradigm, agreement can also occur in the following kinds of cases.
Because the criteria (aims, methods) are different in the two theories, there may be no neutral, algorithmic proof; nevertheless, it often turns out that as the theory develops it begins to look better from both perspectives. (Again, this only makes sense if we deny three theses espoused by Kuhn--namely, that paradigms are self-justifying, that the aims-methods-theories mix that comprises a paradigm is an "inextricable" whole, and that paradigm change cannot be piecemeal.) Thus, adherents of the old paradigm might drop adopt the new methods and theories because they enable them to do things that they recognize as valuable even from their own perspective; then they might modify their aims as they find out that those aims don't cohere with the new theory. (Examples of Piecemeal Change: Transition from Cartesian to Newtonian mechanics (theoretical change led later to axiological change); Transition from Ptolemaic to Copernican astronomy (methodological change--i.e., it eventually because easier to calculate using the methods of Copernican astronomy, though this wasn't true at first--led to eventual adoption of the Copernican theory itself.)
Prediction of the Holist Approach (committed to covariance):
Counterexamples: piecemeal change given above; cross-discipline changes not tied to any particular paradigm (e.g., the acceptance of unobservables in theories, the rejection of certainty or provability as a standard for acceptance of theories)
Because of the counterexamples, it is possible for there to be "fixed points" from which to rationally assess the other levels. "Since theories, methodologies, and axiologies stand together in a kind of justificatory triad, we can use those doctrines about which there is agreement to resolve the remaining areas about which we disagree" (84).
Can Kuhn respond?
(1) The "ambiguity of shared standards" argument - those standards that scientists agree on (simplicity, scope, accuracy, explanatory value), they often interpret or "apply" differently. Laudan's criticism: not all standards are ambiguous (e.g., logical consistency) - A response on behalf of Kuhn: it's enough that some are, and that they play a crucial role in scientists' decisions
(2) The "collective inconsistency of rules" argument - rules can be differently weighted, so that they lead to inconsistent conclusions. Laudan's criticism: only a handful of cases, not obviously normal. No one has ever shown that Mill's Logic, Newton's Principia, Bacon or Descartes' methodologies were internally inconsistent. A response of behalf of Kuhn: Again, it's enough if it happens, and it often happens when it matters most, i.e., during scientific revolutions.
(3) The shifting standards argument - different standards applied, so theoretical disagreements cannot be conclusively adjudicated. Laudan's criticism: It doesn't follow (see earlier discussion of underdetermination and the reticulationist model of scientific change).
(4) The problem weighting argument - Laudan's response: one can give reasons why these problems are more important than others, and these reasons can be (and usually are) rationally critiqued. "...the rational assignment of any particular degree of probative significance to a problem must rest on one's being able to show that there are viable methodological and epistemic grounds for assigning that degree of importance rather than another" (99). Also, Laudan notes that the most "important" problems are not the most probative ones (the ones that most stringently test the theory). For example, explaining the anomalous advance in Mercury's perihelion, Brownian motion, diffraction around a circular disk. These problems did not become probative because they were important, but became important because they were probative.
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