Moorean Facts About Knowledge
For some reason, I find Moore's refutation of idealism ("here is a hand; therefore there is an external world") much more convincing than his refutation of skepticism ("I know that here is a hand; therefore I know that I am not a brain in a vat".) Why is that?
In both cases, Moore's argument would not convince his opponent who would obviously reject Moore's premise. So that's not the difference. I think the difference also isn't that skepticism is a philosophically stronger position than idealism. Rather, it seems to me that the premise against idealism is much more certain than the anti-skeptical premise. That here is a hand (or at least that there are hands) is about as certain as non-logical truths get, that I know that here is a hand is not. If I were to compile a list of Moorean facts -- of facts that are at least as certain as any philosophical argument against them --, I would include all kinds of facts about material objects, other people, experiences, mathematics and modality, but knowledge claims probably wouldn't make the list.
So when Moore makes his list of trivialities, I agree that we know all of them. But when he goes on to use this knowledge -- rather than the known facts themselves -- as a philosophical premise, something seems wrong.
That's odd: if I agree that we know all the trivialities, don't I also believe that we know them? Maybe not. I certainly do not know for sure that I know them. Maybe even "p and I don't believe that p": I know for sure that here is a hand, but I'm not certain that I know that here is a hand. Or so I want to say. But maybe I'm just confused.