Serendip is an independent site partnering with faculty at multiple colleges and universities around the world. Happy exploring!

Reply to comment

Paul Grobstein's picture

Normal and revolutionary science: where's the falsification?

Before turning to Kuhn, we did a little interesting further reflecting on our Popper conversations and, in particular, on the issue of why Popper wanted to hang onto the idea of a "real world" out there independent of the observer despite not being able to access it. To put it differently, why would Popper want to insist on a "metaphysical" starting position for science?

An interesting argument that emerged was that Popper was himself (whether he consciously recognized the implications of this or not) as much interested in "edification" as "elucidation", ie that he felt that the concept of a testable "Truth" was needed in order to get people to be able to come to agreement about things (a social desideratum), to motivate them to move toward "objectivity" (see the "objectivity"/"subjectivity" spectrum). Its an interesting question whether this is actually so different from Kuhn's assertions that science is fundamentally a matter of collective agreement (as below and to come to).

Its also worth noting that appealing to an (unknowable) outside entity is not so different from what is done (with the same objective) by many religions. And that, along with this, Popper also had a similar concern about "universals", constructing a particular theory of science largely because of the inability of inductive/empirical processes to validate them. The falsification program in turn leaves one in the somewhat awkward position of not knowing whether/how to make use of induction, ie be relying on falsifying observations without being able to do much with corroborating ones. A Bayesian approach gives weight to both, as does ordinary "common sense".

All this notwithstanding, Popper unquestionably advanced the conversation about the nature of science. There clearly is something to be said for a way of thinking that could replace, or at least supplement, common sense, history, tradition, social interactions, and religion as a way to make sense of things (at least collectively?). And there is at least a "common sense" appeal to doing so via the concept of a "real world". We do, of course, ourselves frequently make a distinction between what we or others "imagine" and "reality".

Emily did a very nice job of getting us started on Kuhn, and I certainly found, as I did with Popper, that Kuhn warrants multiple readings. An interesting starting point for Kuhn is the issue of "descriptive" vs "prescriptive", ie the notion that Kuhn is taking an historical approach, describing what actually happens in science rather than what should happen (as in Popper). There's an intriguing (and perhaps ironic) possible parallel here to the elucidation (Kuhn?) versus edification (Popper?) distinction that we may want to revisit after further discussing Kuhn).

Kuhn's story of science clearly has features in it that are absent in Popper's, most notably "paradigms" and the distinction between "normal" and "revolutionary" science. Kuhn's story clearly also lacks any dependence on a "world out there" and clearly yields a picture of science more as a social activity and less as the kind of collective of activities of otherwise more or less independent explorers that Popper leaves one imagining.

Most significantly perhaps (at least in our discussion so far), Kuhn's "normal science" (the bulk of science) is not at all an activity of "falsification". In Kuhn's picture, science is largely a matter of "puzzle solving" within a "paradigm" or "world view" (or, as we'll perhaps come to call it, a "reference frame"). It is the paradigim that gives meaning to observations, and that defines the puzzles to be solved and the accepted ways to do so. The objective of the scientist in such a picture is not to falsify the paradigm but rather to expand it, to explore how many things can be made sense of in terms of the paradigm. In this context, an observation can be successful because it solves a puzzle, rather than because it falsifies. And observations that don't "make sense" in the paradigm are taken not as falsifications but rather as 'anomalies", ie they are simply put aside in anticipation of some future understanding that will make sense of them in terms of the paradigm.

One might, of course, entertain the possibility that Popper's "falsification" occurs not in Kuhn's normal science but does in the periods of "crisis", when one paradigm is replaced by another. Kuhn, however, argues quite explicitly that paradigms are not in fact "falsified" by observations at such times. An increasingly heavy set of anomalies" may contribute to a "revolution", to replacement of one paradigm by another, but this doesn't in practice and can't even in principle account for transitions. Any given set of observations can be incorporated in multiple different paradigms (this logical point plays a role in Kuhn's work comparable to the inability to prove univerals inductively does in Popper's). So the replacement of a given paradigm by another different paradigm requires some other explanation.

Kuhn suggests that paradigm replacement has much to do with practical features of paradigms as it does with "rationality", ie with how easy the paradigms are to use and how clearly they define new "puzzles" that scientists perceive as approachable. The associated issues of why paradigms fail and where new paradigms come from clearly needs more attention. How satisfying Kuhn's answers are will, I suspect, be a major topic of discussion in our next meeting as we continue to read Kuhn.

In the meanwhile, though, we started thinking about examples in contemporary phenomena and experiences. The geocentric and heliocentric solar systems can easily be thought of as paradigms, and the replacement of the former by the latter did not involve any "falsifying" observations. "Evolution" (as well as "intelligent design") would also clearly seem to have the characteristics of a paradigm. So too is "molecular biology" and, in this context, the genome project would seem a clear example of "normal science". A noteworthy characteristic of the latter, however, is that it was supported by many scientists on the argument that it would inevitably turn up surprising new observations, and in fact it has. One might then argue that "normal" and "revolutionary" science are not alternatives but rather complements. A carefully constructed map ("normal science") can be used to locate places for new observations that might ultimately lead to a paradigm shift. This suggests that what is at issue in science as a whole may not be quite "falsification" but rather an inclination to replace things that are older and less "useful", with things that are newer and more useful. And that "useful" in this context includes creating new puzzles? new opportunities for exploration?

Some interesting reflections on educational experiences may be relevant here too. Education seems largely to follow a Kuhnian "normal science" pattern, with students mastering paradigms rather than acquiring experiences in how to falsify. Should there be more of the latter? Or is it appropriate given that much of science is necessarily of the "normal" variety?

Some additional issues for further discussion. Might one see Kuhn's "paradigms" as Popper's "metaphysics"? Is it relevant that Popper's "science" is largely a solitary activity and Kuhn's a communal activity? IsKuhn's "lose usefulness" the same as Popper's "falsification"? Is Kuhn actually any more purely "descriptive" than Popper?


To prevent automated spam submissions leave this field empty.
2 + 0 =
Solve this simple math problem and enter the result. E.g. for 1+3, enter 4.