We’re doing Fantl/McGrath in my grad seminar, and it is really great stuff–I’ve had a very high opinion of the book since it came out, but it is interesting to see how blown away the students have been by it. Very neat!
Anyway, the first chapter is about fallibilism, and I’ve been working on the distinction between fallibilism and infallibilism for a bit, finding it perplexing. And there is something really interesting here that I noted.
First some quick background. My interest arises because I’d like to see a characterization of fallibilism and its denial that are both exclusive and exhaustive, making every epistemic theory one or the other and not both. It used to seem simple to do so: one talked about entailing evidence and the failure of such, and that was that. But then along came the Cheap Infallibilisms: Disjunctivism in the theory of perception, the Williamsonian identification of evidence with knowledge, etc. (I’ll add an addendum that shows my own cheap version as well, one that doesn’t endorse E=K, but is built off a deduction theorem in epistemic logic. It’s very cool (perhaps, or in part because, trivial), I think, but you’ll have endure to the end to see it (or skip if you prefer)).
So usual construals of fallibilism fail the exclusive and exhaustive test, settling for a sufficient condition for fallibilism only. That’s fine if all you want to do is make sure you embrace the true view(!), but I want more. And I found something perplexing and interesting in F/M on this score, which I’ll report below the fold.
So, here’s what F/M do. They identify 3 versions of (attempts at stating) fallibilism. The first, entailing conception noted above, they reject because, among other things, it doesn’t distinguish between cheap and real infallibilism. Good point, I say: one can embrace logical infallibilism and bear the same relation to real infallibism–the kind of which Descartes is an exemplar–that decoy ducks bear to ducks.
So, then they describe two other versions of fallibilism, strong and weak, which are:
WEAK: a belief can be adequate without being maximally justified;
STRONG: a belief can be adequate even though the epistemic chance of it being false is not zero.
To understand the difference, and ordering of strength, we need to know something about what maximal justification is and what epistemic chance is. And here’s where it gets interesting.
About maximal justification, they first endorse the idea that any non-entailing justification fails to be maximal, because an entailing one is better. Again, good point. But then they write something that also seems right, but causes a problem. They say (p. 10),
…[S]omething infallibly known in the logical sense can still be fallibly known in the weak epistemic sense. If you know Plato taught Aristotle on the basis of entaling evidence . . . this is still compatible with you justification being imperfect. Your justification might not be enough, for example, to make you reasonable in investing [as much confidence] as you would in other propositions, e.g., Plato is believed to have taught Aristotle, let alone Here is a hand.
This point seems right, and though I think F/M are thinking only about cheap infallibilisms here, the same point can be made about real infallibilisms. Take Cartesian certainty as the exemplar here: if you insist that one has to be metaphysically certain to know, or be justified in believing, you are a real infallibilist. But once you see what F/M say in the last quote, you should or at least might agree about the range of things a successful completion of the Cartesian project would generate. Thus, you might say,
Even though I’m metaphysically certain that I think, and metaphysically certain that I exist, and metaphysically certain that God exists, axiomatic systems work in such a way that one is not always in a position to be as confident about the theorems as about the axioms. So there are distinctions to be drawn between the claim that I exist and the claim that God exists, since the derivation of the latter involves a bit of complexity.
That is, once one makes the F/M point about cheap infallibilisms and entailing evidence, it looks like there is no good reason to insist that the same can’t be said of paradigm, real infallibilisms.
But if that is right, then one can be a weak fallibilist, in F/M terms, and a real, genuine article infallibilist.
The same might also happen with strong infallibilism, unless one adds the proviso that anytime one is metaphysically certain, the epistemic chance of error goes to zero. In the first chapter, they never explicitly endorse such a claim, though I expect they think it is true. I myself can’t tell if this claim is true, because I’m not yet sure what epistemic chances are (I think I have a better idea what objective chance is, or what objective or subjective probability is, but an epistemic chance isn’t any of these.)
So perhaps strong fallibilism will turn out to be incompatible with real infallibilism, which would be a good thing. (It still won’t satisfy my other philosophical urge, because being a strong fallibilist isn’t obviously necessary for being a fallibilist, so I don’t yet get what I want, which is an exclusive and exhaustive taxonomy.) But what’s interesting is that F/M embrace a kind of argument that has a very reasonable extension that makes weak fallibilism compatible with real infallibilism.
So I recommend thinking of weak fallibilism in the way I think of cheap infallibilism: I throw them in the bin with decoy ducks and former senators and dead animals.
APPENDIX: A NEW CHEAP INFALLIBILISM ABOUT EMPIRICAL KNOWLEDGE
Suppose that E is (defeasibly adequate) evidence for p for S, where S is a person and both E and p, where we restrict everything to the domain of contingency. Then, in certain contexts, we’ll get a legitimate epistemic derivation of p from E. Suppose also that we find a deduction theorem attractive within this domain of contingency: if p is derivable from E, then the indicative conditional “if E then p” is derivable from nothing. And suppose one also thinks of all theorems within this domain as included in one’s body of evidence (this won’t work without the restriction to the domain of contingency, since one shouldn’t want all necessary truths to be in every body of evidence, but once restricted to the domain of contingency the view is much more plausible).
So, we then get a cheap infallibism, because in any circumstance in which p is justified for a person by E, that person’s evidence includes both E and the indicative conditional “If E then p”.
An interesting result to this extent: for those don’t appreciate the difference between cheap and real infallibilism, it is nice to find a very general form of the view that, by some attractive logic alone (rather than substantive epistemological commitments such as Disjunctivism or E=K), turns any fallibilist view about empirical knowledge into a cheap infallibilism.