You're right, JTB would say they didn't have knowledge. But why? Is it because it wasn't justified or because it wasn't true? If it's the latter, how can you ever ascertain whether something is or isn't knowledge (i.e. how do you know 'truth')? That's my fundamental problem with this account.
I agree, also, that just defining good knowledge as beliefs based on good priors regresses the problem. I tend to think this regression is unsolvable except in pragmatic terms (what is efficacious when tried against the real world is what is good).
Most folks who do traditional epistemology would say that you could have very good justification yet fail to have knowledge because what you believe isn't true.
And yes, this probably means that in some sense, when you know something, you don't have direct access to the fact that this is knowledge. It's also often the case that you shouldn't be certain that you know. You can't perfectly ascertain whether you have knowledge... though you can have good reason to believe that you know something.
Most philosophers these days deny that knowledge requires either certainty or direct access. For instance, we know lots of things on the basis of testimony and other sorts of non-deductive evidence.
You're right, JTB would say they didn't have knowledge. But why? Is it because it wasn't justified or because it wasn't true? If it's the latter, how can you ever ascertain whether something is or isn't knowledge (i.e. how do you know 'truth')? That's my fundamental problem with this account.
I agree, also, that just defining good knowledge as beliefs based on good priors regresses the problem. I tend to think this regression is unsolvable except in pragmatic terms (what is efficacious when tried against the real world is what is good).