Ive been talking epistemology with a student here at Mises U. this week, and at one point I wrote up a couple of pages for him. So I thought Id share them with the rest of you:
I take your view to be as follows: that genuine knowledge includes a) awareness of our own subjective mental states, and b) the grasp of a priori conceptual truths like mathematics and praxeology, but not c) sensory perception and the judgments based thereon and that the reason for this is that its possible for (c) to be mistaken while its not possible for (a) and (b) to be so, and that while it may be appropriate to believe things that could possibly be wrong, we shouldnt claim to know them. And part of your reason for this latter claim is that treating beliefs that might be wrong as cases of knowledge is equivalent to deciding what knowledge is by randomly throwing darts at a dartboard.
So here are some of my objections (some of these I talked about yesterday, others not):
1. This is not how the word is used in ordinary language. In ordinary language, we regularly apply the word to fallible beliefs; and since use determines meaning, what we ordinarily mean by knowledge seems to be something that does not fit your criteria. So in effect youre proposing to change the meaning of the word knowledge, or youre introducing some special philosophical sense of knowledge different from the ordinary one (call it Knowledge-with-a-capital-K). And then the question is why we should care about Knowledge-with-a-capital-K, as opposed to (what Im tempted to call) real knowledge.
2. I suspect the attractiveness of Knowledge-with-a-capital-K depends in part on a couple of fallacies. One turns on the ambiguity of if I know something, then I cant be wrong about it. Thats true if its read as NEC:(If I know that p, then I am not wrong about whether p); but theres a tendency to shift illicitly from this claim to the stronger claim If I know that p, then NEC:(I am not wrong about whether p). But the latter claim doesn’t follow. (This is called a confusion of necessitas consequentiæ and necessitas consequentis.) The other fallacy is that of sliding from If its infallible, then its certain to if its certain, then its infallible. (Thats called affirming the consequent.)
3. The difference between a priori and empirical knowledge is not that the first is infallible and the second not. A priori knowledge is fallible too. After all, we can make mistakes in math, for example. I might be wrong in thinking that 32794 + 85649 = 118443; maybe I forgot to carry a 2 or something. The difference lies not in whether its fallible or not, but rather in what kinds of evidence are relevant to showing it to be wrong. Objections to empirical claims appeal to empirical evidence; objection to conceptual claims appeal to conceptual evidence.
A related mistake is that of confusing the necessity of the fact stated by a claim with the necessity of our being right about the claim. If its really true that 32794 + 85649 = 118443, then it is necessarily true that 32794 + 85649 = 118443; but likewise if its really true that F=G(m1m2/r2), then its also necessarily true that F=G(m1m2/r2), even though the former is a conceptual claim and the latter is empirical. But we could be wrong about either one.
4. The principle that we can only know things that cant possibly be doubted doesnt seem to pass its own test; that is, it seems possible to doubt (indeed I do doubt) that we can only know things that cant possibly be doubted so by its own standards that claim doesnt count as knowledge.
5. The distinction between what we can know and what its appropriate for us to believe for practical purposes seems difficult to maintain. First, if I cant know that theres a table in front of me, then I cant know that I have good practical reason to acts as though theres a table in front of me either. Second, if a belief isnt justified, then by definition we shouldnt believe it; so there doesnt seem to be room for a class of beliefs that are unjustified but that should be accepted for practical purposes. Third, its difficult to accept a belief and yet claim not to know it; p, but I dont know whether p seems Moore-paradoxical.
6. I think your position makes sense-perception impossible. After all, if I look at a table and have a hallucination of a swan, my experience of the swan doesnt count as my perceiving the table. Yet similarly, if I look at a table while simultaneously having a hallucination of a table, that doesnt count as my perceiving the table either. But what if my sensory experience of a table is caused by the table; in that case is it now a genuine perception rather than a hallucination? On my view, sure; but I think your view requires you to say otherwise. For if you really think that a belief thats only probably true is no better off, knowledge-wise, than throwing darts randomly at a dartboard, then I think you also have to say that as long as our experience of a table could be caused by something other than an actual table, then its status is equivalent to that of a hallucination even when, as chance has it, its caused by an actual table. And that means that we never make genuine cognitive contact with the world through perceptual experience at all; were always merely hallucinating, though some of our hallucinations are accidentally accurate. And as a result, all our knowledge of the world is hypothetical; we can know that if there are 2 + 2 bottles on the table, then there are four bottles on the table, but we cannot know whether there are actually any bottles on the table or indeed anywhere else.
I think what this view advocates then, is a kind of pathological alienation from the world. It means that youve never actually seen or touched a physical object; youve only theorised about them. Likewise youve never actually seen or touched another person; again, youve only theorised about them. The attitude your view seeks to inculcate has characteristics of mental illness.
More to the point, I think its incoherent. Heres why. The ability to apply a concept (not exceptionlessly, but at least with reasonable reliability) is part of having the concept; we dont count as having a concept unless we know how to apply it. After all, the process of acquiring a concept just is the process of learning to recognise and identify instances of it in our environment. But its an upshot of your view that we have no such ability to recognise and identify anything in our environment. But that would mean that wed be unable not just to know but even to conceive of physical objects, or of minds other than our own; wed be driven to solipsism.
For example, since we can identify agency only in our own case (I would claim we couldnt even do that since agency is a general concept its possession requires ability to apply it to more than one case but never mind that for now), we can never apply the concept of interpersonal exchange, since that requires more than one agent. But that in turn would mean that we cant even have the concept of interpersonal exchange thus, rendering praxeology impossible. (Thats what I meant in saying that we couldnt even have praxeology unless our fallible empirical beliefs counted as knowledge.) Since in fact we do have the concept of interpersonal exchange, that shows that our ability to identify such exchanges is genuine even though its fallible. (Thus the skeptics inference from you could be wrong in any particular case to you could be wrong in all cases simultaneously doesnt go through.)
A related point: you seem to accept uncritically the Humean empirical conception of perceptual experience. (Ditto for Hoppe when he says we can only perceive correlations and not causings.) The point of a Kantian approach is not to turn the realm of perception over to Hume but then retreat to a higher conceptual realm; rather its to claim that the perceptual realm is already conceptually ordered.