StephenLawrence - 15 March 2008 02:51 AM
(1) For our ‘common sense’ use of the word certainty to makes sense does there have to be such a thing as absolute certainty?
(2) Can I claim that I’m almost certain of something, with out it being possible to be absolutely certain?
Stephen
You’ve asked two rather different questions, both really interesting.
The first question is very general: I think that evaluations like ‘less or more certain’ just entail the superlative ‘utterly certain’ - more generally, evaluations entail standards. That would take some argument of course.
But maybe we don’t need to know that standard (and maybe they don’t exist - that’s a common thing to deny nowadays, and my opinion is a minority among philosophers, FYI). You can compare[i/] one proposition with one you do accept as ‘sure’.
Something like this: “Well, I’m more sure physics is right than that you saw Caspar, a ghost, walk through a wall then pick up a knife.” After all, if he walked thru a wall then he doesn’t interact with matter, but there he is interacting with the matter of the knife, and so on. You might not be absolutely[i/] sure of physics, but you’re more sure of it than the observation of Caspar’s wall-walking and knife-handling. (Maybe you’d get generous and pick apart the conjunction: maybe the guy saw ‘a ghost’ but he was wrong about the wall part, or the knife part, or even the ghost part - it was a someone, ‘a Caspar’, but it was George in a ghost-costume with a cool new technological gadget.)
So you don’t have certainty, but you can have more or less uncertainty. There may still be[i/] real certainties, but they might not play a direct role in human knowledge, so it would be moot to say if we can have[i/] them. We might still pursue them. I want the[i/] theory of physics, the one that’s completely true in all specifics, not its close cousin - but i might only obtain at any time a theory close to the really right one.
On the second question, think of Newtonian physics. You, an 18th-century educated man, could naturally and justifiably be sure enough that it’s the best theory without ever claiming it’s right in every aspect - you might even acknowledge that there’s errors in it somewhere. Like the woman who writes a book, and after combing through it she can still say that ‘There’s errors in this book” but because she just doesn’t know which ones they are (or she’d have changed them!), the book stands correct enough as it is.
So you can be ‘sure’ of a sentence (or proposition, or a set of them like a theory - i’ve been using all of these a little loosely) without being equally sure of every part of it.
A skeptic about knowledge will have an attack for all of these.
Kirk
