Kuhn, Normal Science

Kuhn's method is historical and, to some extent, sociological

It was a big shock to a lot of people that, in doing philosophy of science, it was actually useful to know something about what scientists do.

The historical method has a problem: distinguishing the descriptive from the normative.

Paradigms

A paradigm is an examplar, an example to be imitated or followed. Kuhn used the word in 23 different special ways. He emphasized that science is not about theories and evidence, but about paradigms. Scientists try to do new things, and so a theory and old experiments can't be literally just applied. So, what do you actually do? You try to extend what worked by imitating it. What serves as a paradigm? Particular experiments, particular ways of getting funding, particular tricks for solving equations, particular approaches to formulating problems. Kuhn called each of things individually a paradigm, and he called a whole system of them a paradigm too.

Normal Science

Kuhn thinks that there are two kinds of science, normal science and revolutionary science. Normal science is science practiced within a fixed paradigm. In normal science, nothing gets questioned except your own abilities. You don't confirm, verify, theorize at all, in any direct sense. You push your paradigm a bit further. Not every problem has been solved, there are always new things to try, and so you work them out. If it doesn't work, does that show the paradigm to be wrong? No, it just shows you weren't good enough at it.

Anomalies

Every paradigm is surrounded by anomalies, that is, experiments that fail, measurements that disagree, equations that can only be solved approximately and give the wrong answer. In other words, in Popper's terms, every theory in every paradigm is falsified, even as scientists continue to use it.

This came as a great shock to standard empiricists: Scientists do not have an open mind about the truth of their theories, and they "never" take an experiment to falsify a theory. When things go wrong, they don't renew the scientist's grant. The most revolutionary part of Kuhn's philosophy of science is that he took this narrow-mindedness to be a good thing, a central part of the success of science.

Why is normal science a good thing? According to Kuhn, at least in part because the resulting stubbornness leads to pushing theories and experimental techniques as far as possible and as a result accumulating useful techniques and information. Note something extraordinary about that reason: it is an empiricist reason. The supposedly antiempiricist norm of Kuhn—that normally scientists should hang on to their beliefs in the face of any evidence whatsoever—is justified on empiricist grounds.

Crisis

A crisis results in a change of paradigm. What precipitates a crisis? Kuhn's answer is complex.

-- ShaughanLavine - 21 Sep 2005 - 19 Sep 2007