Relevant to the previous post and discussion in this blog, is an essay by Sean Carroll from Cosmicvariance on What I Believe But Cannot Prove. With regards to scientific belief he has this to say:
"There is no sharp bright line that we cross, at which the idea goes from being 'just a theory' to being 'proven correct'. Rather, maintaining skepticism about the theory goes from being 'prudent caution' to being 'crackpottery'."
Particularly relevant (to the exchange between Jego and me in the previous post), is the following passage:
"'Proof' has an interesting an useful meaning, in the context of logical demonstration. But it only gives us access to an infinitesimal fraction of the things we can reasonably believe. Philosophers have gone over this ground pretty thoroughly, and arrived at a sensible solution. The young Wittgenstein would not admit to Bertrand Russell that there was not a rhinocerous in the room, because he couldn't be absolutely sure (in the sense of logical proof) that his senses weren't tricking him But the later Wittgenstein understood that taking such a purist stance renders the notion of 'to know' (or 'to believe') completely useless"
Worth reading the whole thing.