Kuhn: Intro, Normal Science

1. Kuhn: Intro, Normal Science Shifting ground

2. The Structure of Scientific Revolutions • This is the most influential book on philosophy of science of the last half of the 20th century. • Kuhn is, first, a historian of science. • His focus, as a result, is on real cases from the history of science, rather than on the logic of simple examples like those pursued by most proponents of logical empiricism.

3. Some key Kuhnian concepts • Paradigms as standard examples of good science, guiding further inquiry. • Normal science as puzzle-solving. • Revolutionary science as methodologically unconstrained. • Incommensurability of successive paradigms (even in the same field). • Consequent lack of objective, logically conclusive grounds for preferring one paradigm to another– the conversion metaphor. • Observation is theory-laden.

4. Paradigms • This word was a big success, widely adopted following Kuhn’s book. But it was philosophically protean, which is a dubious thing. • More than a dozen distinct uses were noted (21 are cited by GS); Kuhn was embarrassed, and settled on one meaning for the word: A standard example of good science. • We can’t fully state what such examples teach, we can’t give explicit rules for doing things ‘that way’, but a paradigm is still a powerful influence on the scientific work that comes afterwards.

5. Broad Paradigms • Beyond the more narrow and specific sense that Kuhn later adopted for ‘paradigm’, there is also a broader sense, in which a paradigm is an entire way of doing science. • The narrow, ‘exemplar’ reading is crucial because we can’t describe it fully (you’ve got to look to the exemplar to really understand the paradigm).

6. Ways of doing science • These include value-laden ideas about what problems are most important to solve, and about what counts as a good solution. • They also include ideas about observation– For Kuhn, observation is not universally shared across different paradigms– the basic concepts that make up a paradigm’s world view affect how its proponents understand what they observe.

7. Relativism? • Both the values that might guide a choice between paradigms and the observations that we make actually vary for different paradigms– this makes the rationality of choices between paradigms a very subtle business. • Relativists endorsed Kuhn’s views, claiming that they supported their skepticism about the objectivity of science. • Kuhn was always unhappy about this endorsement, and resisted the simple view that such choices are irrational.

8. Contrasts • Kuhn sees normal science as not aiming to falsify theories/paradigms– instead, scientists working in this mode assume that some successful solution fitting the paradigm is available. After all, it’s a poor worker who blames his tools… • But, recalling Maxwell’s paper from last week, this tension could easily be resolved by treating this aspect of normal science as a way of ensuring that we don’t take a theory to be falsified until it has been given a full and fair chance to resolve its difficulties.

9. Different ‘moments’ in science • The contrast between normal and revolutionary science suggests that there is not a single, uniform scientific method. • But again, Maxwell’s account of Popper suggests that this difference could also be tactical, a matter of responding differently to different circumstances, in ways that enable us to pursue Popperian goals more effectively over the long term.

10. Norm and Description • Kuhn presents his account first of all as descriptive: it’s an attempt to tell us how science has been done, to describe the methods and the kinds of behaviour that occur in both normal and revolutionary science (and during the crises that leads us from one to the other). • But what does this tell us about how science should be done? • What goals does science pursue? Can Kuhn’s description of science show us that this practice will help us achieve such goals?

11. Progress and success • Progress is pretty easy to discern in normal science– so here an instrumental, means-end account of rationality makes sense. • But when it comes to revolutions, it’s very difficult to say whether progress has really occurred– by the standards of the previous paradigm, crucial insights have been given up, established observations overturned (and re-interpreted). The new paradigm, of course, says that its new ideas are just the ticket– but that’s not an objective standpoint to decide the issue from!

12. The success of science • For Kuhn these activities are all part of what makes science so successful– despite the role of rigid, strict training, commitment to a paradigm, how the paradigm confines what we observe and how we think about the world, they are all essential to the success of normal science. • And despite the anarchy of revolutionary science, it too contributes to the overall success of science, by leading us to break out of dead-end paradigms.

13. Origins of a paradigm • Science begins without a paradigm, in ordinary, common sense investigation of the world (or some particular aspect of it). • But as such investigation continues, some example or other comes to light as a great success, promising further insights. • This becomes a paradigm in the narrow sense, leading to the development of a broader paradigm as new work grows around this exemplar, identifying a program of work and a set of puzzles ready for scientists to work on.

14. Examples • Skinner’s behaviourism.(GS) • Molecular genetics.(GS) • Also worth considering: • Plate tectonics • Copernican astronomy • Evolution • Radiological dating • Each constitutes or is associated with a way of doing science, each has standard examples of good work that students are trained to understand, etc.

15. Normal Science • Here scientists operate under a paradigm that has consensus support. • Problems are worked on under the presumption that a suitable solution of the type exemplified by the paradigm will emerge. • This activity is conceptually straightforward, in that we know in advance what sort of result would count as a solution– Kuhn describes it as ‘puzzle-solving’.

16. Crisis • As more and more solved puzzles accumulate, normal science delves deeper and deeper into the phenomena it is attempting to understand. • Anomalies, unsolved puzzles that seem to be timely and yet resist solution, tend to accumulate as deeper issues are dealt with. • When some of the central problems of the field become anomalous (and esp. when a pattern of anomalies and arguments that seem to make them unresolvable develops), a crisis is under way.

17. Puzzles for Kuhn • Just one paradigm at a time? • Aren’t scientists really more open and flexible (often even able to understand and respond sympathetically to alternative paradigms)? • Do we really need narrow, rigid commitment in order to push a paradigm as hard and as far as we can?

18. The vulnerability of science • The story of A-life: a failure to get a paradigm started (and the evils of over-eager commercialization?). • A final, related point: Research shows that providing excessive monetary rewards for various kinds of scientific accomplishment (patents, new processes, etc.) actually reduces the productivity of research scientists– they seem to do better when they keep their minds on the intellectual puzzles rather than dangling carrots…

19. Revolutions • Sometimes, however, problems that are important and ripe for solution turn out to be resistant. • Such problems can undermine confidence in the paradigm and give rise to a period of ‘revolutionary science’. • Rather than solve puzzles, scientists engaged in revolutionary science set aside the established paradigm and search for new ideas– this is conceptually rich, and unguided by any clear methodological constraints: everything is on the table.

20. Incommensurability • This is a problem about how to compare the pre- and post-revolutionary paradigms. • Because the standards for what good science is are embodied in these paradigms, sciences guided by different paradigms are extremely difficult to compare in any fair way. • Kuhn describes adopting a new paradigm as more like ‘conversion’ than any rational sort of persuasion.