Philosophy

While McMullin's criticisms of Kuhn came in the defense of Scientific Realism, Laudan has no such ax to grind. That is, Laudan takes Kuhn to task not so much for his rejection of Scientific Realism as for his conclusion that there is no rational or evidentiary basis for paradigm choice during periods of scientific revolution for want of inter-paradigmatic standards or common observations, respectively.

Kuhn's mistake, Laudan argues, is to have uncritically adopted a particular model of scientific rationality without considering alternatives. Thus Laudan exploits a peculiar weakness of Kuhn's argument: We nowhere quite get full account of paradigms, apart from the rather striking claim of holism so as to draw the twin conclusions of the theory-dependence of theoretical terms and the theory-ladenness of observation.

Laudan proposes that we think of all paradigms as containing three essential levels:

1. The Axiological Level, which describes the values and aims of science itself;
2. The Methodological Level, which provides inter-theoretic standards for the comparison and evaluation of particular scientific theories, how experiments are best designed and conducted, and rules about what counts as evidence; and,
3. The Factual Level,, which develops theories about the processes and entities presupposed by the paradigm itself and the level at which most scientists work most of the time.

Notice that particular scientific theories are not seen as paradigms themselves. Rather, they are smaller parts of a much larger 'whole-science' consensus which Laudan identifies as the paradigm.

Now, Laudan claims that there are at least two models of scientific rationality:

1. The Hierarchical Model
   • Justification is top-down. That is, scientists invoke the Methodological Level to settle disputes at the Factual Level. Likewise, disputes at the Methodological Level are settled by drawing on the resources of the Axiological Level. Thus, where '->' designates 'justifies', (1) -> (2) -> (3).
   • Justification is linear. That is, there are no judgments at the Axiological Level made by reference to the Methodological Level or the Factual Level. Similarly, there are no judgments at the Methodological Level made by reference to the Factual Level.
   • There is no rational justification of the Axiological Level. That is, nothing in turn justifies the Axiological Level on the Hierarchical Model. Disputes at that level cannot be resolved by reference to any higher level, since there is no higher level to be invoked. During periods of scientific revolution, according to Kuhn, we have disputes between paradigms at the Axiological Level being settled--if it can be called that--purely by sociological and psychological factors having no rational basis whatsoever.
   • Paradigms are holistically complete. That is, intra-paradigmatic justification is the only justification possible, since there is no way to compare paradigms with respect to standards or evidence.
2. The Reticulational Model
   • Justification is top-down and bottom-up. For example, Laudan points out that the aristotelian aim of science to achieve certain knowledge--an issue at the Axiological Level--was long ago abandoned in light of problems discovered at the Methodological Level (problems we shall take up later in the semester).
   • Justification is non-linear. That is, claims made at the Axiological Level are subject to review in whole or piecemeal by claims at the Methodological and Factual levels. Similarly, portions of the current Methodological Level can be adjusted by reference to both Axiological and Factual claims.
   • Paradigms are not holistically complete. That is, since the various parts of a paradigm can be revised piecemeal, it is not the case that a paradigm must either be accepted or rejected whole cloth. Instead, paradigms can be revised over time by internal adjustment and revision, these revisions each earning justification by the tribunal of other, less controversial portions of the paradigm.

The upshot is that Kuhn was far too quick to abandon the possibility of rational progress in science by adopting the Hierarchical Model of scientific rationality without considering the possibility of the Reticulational Model. For on that model, paradigms make progress as they are revised and improved so as to remove internal tensions and improve the likelihood of achieving the goals of science while at the same time assessing those very goals. Even if paradigms aren't always rationally adjusted or contrasted one to another, the possibility remains that paradigms may bootstrap themselves into better achieving the aims of science.