The pessimistic induction and Descartes’ evil demon
The pessimistic induction (PI) says something like this: Previous scientific theories have been wrong, so we shouldn’t believe what current science tells us. But let’s modify that with an “optimistic induction” that there is continuity through theory change (the wave nature of light survived the abandonment of the ether theory…) and our methods are improving. The PI then seems to be saying something like this: It might be the case that this or that particular theoretical entity will be discarded some time in the future. Well, this “might” claim looks a lot like Descartes’ evil demon argument for radical scepticism.
Descartes’ argument says that you might be being tricked by a powerful evil demon. The upshot is supposed to be a radical scepticism about the reality of the things we think we see. So I see a table, but I might be being tricked, so I should not believe the table exists. But obviously this brand of radical scepticism is not the orthodoxy. Why? Because another way to approach the evil demon is a kind of “fallibilism” that holds that I should believe that what I see exists, while accepting that I might be wrong, I might be being tricked by this demon.
In much the same way, I think the right approach to the PI (as moderated by the optimistic comments made above) is to say that the right approach is a “fallibilist realism” which says that while I can be confident that some element of current science will be discarded, on the whole I should believe in theoretical entities.
I think this picture fits nicely with scientific practice as well. Doing science whilst not endorsing the reality of the entities one deals with seems difficult. I mean, if I were a scientist and I didn’t believe in electrons, I’d find it difficult to theorise about them… Or to put it another way, if I were a young creationist, I would not become a paleontologist. (OK, cheap shot. Sorry). The point is that on the whole, scientists will believe in what they study, but will of course accept they might be wrong.
So this point seems obvious enough that I’m surprised I haven’t read about it before. I’m interested in hearing about any precedents of this position in the literature.