Popper's Champion — It is daunting indeed to debate a man named “Rafe Champion“, a name that evokes race car-driving secret agents, or a dangerous, seething, family-wrecking hunks from a “daytime drama”. Shows what you get when you disagree with the redoubtable Perry de Havilland: set upon by mercenary indedependent scholars named “Rafe Champion”.
Anyway, Champion believes that Popper's epistemology solves some puzzle that needs solving. Popper's work makes most sense understood as a response to the deficient epistemologies of the Vienna Circle positivists, such as Carnap, Hempel and company, but I shall not bore anyone with a rehearsal of that history. In any case, Champion argues that it is incorrect to understand scientific knowledge as a species of belief, and that Popper provides a way forward after the alleged failure of the “justified true belief” account of knowledge. According to Champion, in the classical epistemologies “there is no way to decisively (certainly) justify the beliefs that are supposed to be true.”
First, I am keen to know what knowledge is, if not a kind of belief. If I know that water is H2O (a scientific proposition), don't I also believe it? Next, I find that I'm able to decisively justify all sorts of beliefs on the basis of experience. For instance, that there is a mug on my desk. I see the mug on my desk, and I thereby know that it is there. Science is rather more complex than looking at mugs on desks, but one surely can derive certain beliefs from the evidence of the senses. It's not clear to me what bind Popper is getting us out of.
Everything Champion says about the imaginative, critical, entrepeneurial nature of science is consistent with just about every account of scientific discovery. Now, although a few scientists with dated educations are avowed Popperians, Popper's theory fails to describe the actual successful practices of the scientific community. Scientists do in fact count positive experimental evidence, and other indications of theoretical success, such as simplicity, comprehensiveness and so forth, as confirmatory, and they are not wrong to do so. Scientific practice is more Bayesian than Popperian, and because scientific practice is so successful, I am inclined to think the scientists are doing something right. (I will resist the temptation to discuss the problem of prior probabilities.)
Last, I said nothing about limiting science to collecting confirming instances. All I was saying is that Popper is wrong that positive instances don't raise the probability of a hypothesis. According to Popper and Champion, the probability of Newton's theory being true, even after all its success, was the same as the probability of cats giving birth to elephants. And that's absurd. Champion says that my arguments against Popper are “weary and worn out”. This isn't quite to say that they are false, is it? Rather, it says that they are often used. And one might well wonder why that is.