In lecture three of Dynamics of Reason, Friedman addresses problems of relativism and rationality. This is needed since he leans so heavily on the picture of science coming out of Kuhn which on its own tends to invite charges of bad relativism.

Friedman thinks that Kuhn’s responses to the charge of bad relativism are inadequate. I’m not going to go through them though. Friedman’s response begins by noting that Kuhn fails to distinguish between instrumental rationality and communicative rationality, which distinction is suggested by Habermas. Instrumental rationality is the capacity for means-ends reasoning given a goal to bring about, Communicative rationality “refers to our capacity to engage in argumentative deliberation or reasoning with one another aimed at bringing about an agreement or consensus opinion.” (p. 54) Friedman says that instrumental rationality is more subjective while communicative rationality is intersubjective. A steady scientific paradigm underwrites, to use Friedman’s phrase, communicative rationality. Revolutionary science then seems to threaten communicative rationality. A similar sort of worry arises for Carnap and his multiple linguistic frameworks.

At this point it is unclear to me how Kuhn’s failure to distinguish these two kinds of rationality hurt his responses.

Friedman thinks that the scientific enterprise aims at consensus between paradigms as well as within a paradigm. It does this in three ways. One is exhibiting the old paradigm as a special or limiting case of the new paradigm. For example,
Newtonian gravity becomes a special case in relativistic gravitational theory. Friedman sketches a similar exhibition of Aristotelian mechanics as a special case of classical mechanics. This is highly anachronistic but Friedman thinks the proper response emerges when we take a more historical view. He says that the concepts and principles of the new paradigm emerge from the old in natural ways. He thinks it aids nothing to view scientists from different paradigms as speakers of wildly different and incommensurable languages. He says, “In this sense, they are better viewed as different evolutionary stages of a single language rather than as entirely separate and disconnected languages.” (p. 60) (Friedman does say this transition is “natural” in a few places, e.g. p. 63. He doesn’t say what he means by natural which seems to form the crux of his claim here. I’ll come back to this.)

Friedman goes on to say that another way in which inter-paradigm consensus is aimed at is by successive paradigms aiming at greater generality and adequacy. One example is in the move from Aristotelian mechanics to classical, a Euclidean view of space is retained while a hierarchically and teleologically ordered spherical universe is discarded. He unfortunately doesn’t address the issues raised by Kuhn on this point that it is hard to say what is meant by generality and adequacy here. Successive paradigms take up many new questions to be sure, but they also discard many old questions and solutions. They may, in fact, change what counts as adequate. This seems like an odd omission at this point in the dialectic.

Friedman reviews these points, that successive paradigms aim at incorporating old paradigms as special cases and that new concepts and principles should evolve out of old. He says that “this process of of continuous conceptual transformation should be motivated and sustained by an appropriate new philosophical meta-framework, which, in particular, interacts productively with both older philosophical meta-frameworks and new developments taking place in the sciences themselves. This new philosophical meta-framework thereby helps to define what we mean … by a natural, reasonable, or responsible conceptual transformation.” (p. 66) This bit of discussion is preceded by a quick sketch of the regulative principles of current science approximating those of “a final, ideal community of inquiry,” which apparently has some affinities to Cassirer’s view. (I skipped it because it didn’t shed light on things for me.) Friedman gives some handwavy descriptions about how philosophical meta-frameworks determine what is a natural transformation, but it is postponed to one of the essays in the second half of the book. Up until this point, philosophical meta-frameworks didn’t enter into the discussion, so it seems a bit unmotivated to bring them in here. There were some things left unresolved, but claiming that a philosophical meta-framework resolves them is unsatisfying. The follow up essay might resolve this.

One of the examples of a philosophical meta-framework in action that Friedman gives is the debate between Helmholtz and Poincare on the foundations of geometry against the backdrop of Kantian views. While both Helmholtz and Poincare were philosophical, it doesn’t reflect too well, I would think, on their philosopher contemporaries that they didn’t produce more (or are cited as producing more) of the philosophical framework. This particular example has a hint of claiming work by those who are more squarely in the camp of mathematical physics for the philosophical camp. I’d rather avoid going into discussions of disciplinary boundaries, but this seems like a weak justification for (or a weak example of a success of, I’m not sure which it is supposed to be) scientific philosophy. Maybe this indicates something that Friedman thinks, namely that philosophers should be more engaged with, perhaps primarily engaged with, doing hard work in the hard sciences.

At the end of the lecture, I am still wondering how the distinction between communicative and instrumental rationality was crucial. The distinction seemed to fade to the background pretty quickly and do little work. Friedman’s points about inter-paradigm consensus were similar to ones that Kuhn discusses in Structure, so I’m a bit unclear on how Friedman’s were adequate whereas Kuhn’s were not. The follow up essays might clear things up, but I don’t plan on reading them any time soon.