by Scott F. Aikin and Robert B. Talisse
Fallibilism is a philosophical halo term, a preferred rhetorical mantle that one attaches to the views one favors. Accordingly, fallibilists identify their view with the things that cognitively modest people tend to say about themselves: I believe this, but I may be wrong; We know things but only on the basis of incomplete evidence; In the real world, inconclusive reasons are good enough; I'm open to opposing views and ready to change my mind. But there are different kinds of epistemic modesty, and so different kinds of fallibilism. Let's distinguish two main kinds of fallibilism, each with two degrees of strength:
Weak: It is possible that at least one of my beliefs is false.
Strong: Any one of my beliefs may be false.
Weak: It is possible that I know something on the basis of inconclusive evidence
Strong: All I know is on the basis of inconclusive evidence
Belief-fallibilism is a commitment to anti-dogmatism. It holds that one (or any!) of your beliefs may be false, so you should root it out and correct it. The upshot is that one should hold beliefs in the appropriately tentative fashion, and face disagreement and doubts with seriousness.
Knowledge-fallibilism is a form of anti-skepticism. It holds, against the skeptic, that one does not need to eliminate all possible defeaters for a belief in order to have knowledge; one needs only to address the relevant defeaters. The knowledge-fallibilist contends that the skeptic proposes only the silliest and least relevant of possible defeaters of knowledge. We rebuke the skeptic by rejecting the idea that all possible defeaters are equally in need of response. Again, the knowledge-fallibilist holds that knowing that p is consistent with being unable to defuse distant skeptical defeaters; knowing that p rather requires only that the relevant defeaters have been ruled out.
Although these two varieties of fallibilism are propositionally consistent, they prescribe conflicting intellectual policies. Belief-falliblism yields the attitude that, as any of one's beliefs could be false, one must follow challenges wherever they lead. But knowledge-fallibilism holds that one needn't bother considering certain kinds of objections; it thereby condones the attitude that a certain range of challenges to one's beliefs may be simply dismissed.