In Vallicella's A Quasi-Pyrrhonian Metaphilosophical Puzzle, he writes:
I accept (1) on the basis of strong inductive evidence which renders it rationally acceptable. Accepting as I do (1), (2), and (4), I must reject (3). Well, why not?
Why can't I say the following?
3*) A philosophical thesis is rationally acceptable just in case there are some good arguments for it accepted by some competent practitioners.
Consider Barnes's principle of disagreement:
P) If someone is aware that there is an undecided dispute about ?Q, then he ought not to accept or reject any proposed answer to ?Q.
(P) seems to entail (3). For if I can't be aware that there is (rationally) undecided dispute about ?Q and be warranted in accepting any proposed answer to ?Q, then I can be warranted in accepting an answer to ?Q only if there is at least one good argument for it that doesn't "cancel out".
Or perhaps this is all too fast.
I summarize Barnes's argument for (P) here.
Skepticism will continue in three weeks. In the meantime, check out Vallicella's article.