The Virtues of False Belief - A Puzzle

Stephen Stich

Sorry, it's been a slow week on the blogging front, and this is likely to continue on into next week. Here's something to tide you over until I get back to more frequent posting. It's essentially a paradox -- or, at least, I think it might be a paradox -- and I'd like your thoughts on it.

What I want to do is to look at a passage from Stephen Stich on the virtues of false beliefs. It's actually taken from an article by Michael Bishop and J.D. Trout on their epistemological theory Strategic Reliabilism (SR). The passage contains the paradox, but some background might be appropriate before quoting it, so here are the essentials: SR recommends that we adopt belief-forming strategies that are robustly reliable and efficient. In defending this, Bishop and Trout appeal to the Aristotelian principle that, in the long run, good reasoning tends to produce good outcome. Stich criticises this appeal because it reduces SR to a crude form of pragmatism. In other words, it would allow us to pick epistemic strategies that produce false beliefs simply because those beliefs will lead to better outcomes.

Here's what Stich says on this point (from p. 1059 of Bishop and Trout):

[I]n some very significant situations, having false beliefs leads to better outcomes than having true beliefs. Though examples are legion, perhaps the best known comes from the work of Shelley Taylor and her colleagues who have shown that 'positive illusions' and 'unrealistic optimism' in patients with HIV leads to both better psychological coping and slower progression of the infection. To put the matter simply, if you have false beliefs you live longer and have a higher quality of life.

Now I don't know much about Shelley Taylor and her work on HIV patients, but something about this passage struck me as being odd. If optimistic beliefs about one's future disease progression lead to better outcomes, then in what sense are those beliefs false? Surely, those who were optimistic were right to be so since they did, as a matter of fact, live longer and have a better quality of life?

On the face of it, Stich's claims about false beliefs seem paradoxical. At least, they seem that way to me. But I wonder if more could be said. The way I see it there are two interpretations of "false belief" at work here, and each can be used to support a different conclusion. As follows:

• (1) A belief about one's future disease progression is false if it is based on a faulty inference from existing evidence concerning patients with the same disease.
• (2) The patients in Taylor's HIV study drew faulty inferences from existing evidence about patients with the same disease.
• (3) Therefore the patients in Taylor's HIV study had false beliefs.

Or:

• (1*) A belief about one's future disease progression is false if, as a matter of fact, it does not correspond with the actual progression of one's disease.
• (2*) The optimistic beliefs of the patients in Taylor's HIV study did correspond with the actual progression of their disease.
• (3*) Therefore, the patients in Taylor's HIV did not have false beliefs. 

One problem with the second argument is that I don't know if (2*) is true because I don't know the content of their beliefs. It may be that their beliefs were completely out of line with reality but that they still did better than those with more pessimistic beliefs.

Anyway, here are my questions to you: Is there something paradoxical about Stich's false belief example? Does it simply highlight the difference between different epistemological theories? Or am I just being incredibly naive about the whole thing? Answers on a postcard (or in the comments section)