Rafe Champion puts the intellectual boot in one again in the latest round of the Interblog Popper WarsTM
The debate between Karl Popper and his opponents has not advanced very far in seven decades and it is tempting to conclude that it is a waste of time to argue with philosophers about these things. In my view the fault lies entirely with Popper’s opponents who clearly demonstrate that “true belief” theories of knowlege produce “true believers” who persist in their beliefs regardless of effective counter-arguments. Because most of the evils in the world can be attributed to the activities of fanatics (people who are not prepared to reconsider any of their “true beliefs”) I am prepared to persist for a few more rounds of this debate in the hope of explaining how some ideas from Popper and his colleague Bill Bartley can help us to move on. In the meantime, I think that those “rationalists” like Will who persist in defending “true belief” theories of knowledge are in fact “selling the other guy’s product” (that is, irrationalism).
Recall my previous contribution where I explained that critical rationalism is concerned with forming and testing “critical preferences” for scientific theories or social policies (or anything else) so that our preferences can change in an orderly fashion in the light of new evidence or new arguments. For this reason I do not agree with Will’s insistence:
that Popperianism is at bottom a skeptical philosophy of darkness, which, despite the enthusiastic rationalist rhetoric of Popperian advocates, shares more with Rorty-like post-modern pragmatism than pro-reason philosophies of light.
He wrote (in criticism of the Popper’s view that we cannot achieve certainty):
For my part, I have not been made to see what is wrong with being certain in seeing mugs on desks, nor in the problem of a proposition becoming more likely true in light of new evidence
By all means be certain (in your own mind) about mugs on desks and anything else, but bear in mind that our senses are fallible as proved by optical illusions, hallucinations and bad calls by referees and commentators in fast-moving sports. Subjective certainty proves nothing, certainly it does not prove the truth of any general scientific or moral principle. So much for that oft repeated criticism of Popper.
As for a proposition becoming “more likely true” or more probable in light of new evidence, the problem for Will and his mates is to produce the formula to indicate the supposed increase in likelihood or probability. Popperians have no argument with the proposition that there are true propositions, the problem is to know whether any particular (contested) proposition is true or false.
Will wrote:
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
There are two ways of talking about probability. One is when we say that Team A will probably beat Team B in a forthcoming football game. We usually mean that we have formed a critical preference for Team A, given what we know about the game and the two teams. We may sensibly add provisos regarding dud decisions by the referee, injuries to key players etc etc. and the possibility of an upset. That is Popperian and it has nothing to do with a formula that provides a numerical value (p) attached to the proposition “Team A will win”.
Scientists use that kind of “probability” talk when they compare the relative merits of competing scientific theories. We know that Newton’s theory is not true, despite its immense improvement on earlier theories, so it is doubly absurd to think in terms of the (numerical) probability of its truth. What century is Will living in?
The other type of probability is an academic industry that has been around for some hundreds of years, devoted to producing a formula that assigns a numerical value (p) to propositions (h), in the light of various bits of evidence (e). Because no usable formula has yet been obtained for that purpose, one can only conclude that this line of thought has failed, by its own standards. I know that highly learned “Bayesians” can produce formulas but equally learned critics point out that they do not work. Sorry fellas. Thanks for refraining from talk about prior probabilities. That will only land you in a regress that takes you further away from useful talk about the strengths and weaknesses of scientific theories (and football teams). That is the direction of induction and attempts to justify “true beliefs”. It does not help working scientists or anyone else. It is worth noting that Popper is the only philosopher of science who has been taken seriously by any considerable number of scientists who are sensitive to the philosophical dimensions of their work (instances are Einstein, Medaware, Eccles and Monod).
Rafe Champion (Australia)
