L. S. Carrier

If skepticism is once again fashionable, then much of the credit must go to Peter Unger who gives a sustained defense of an ultra-pyrrhonian position in his book, Ignorance: A case for Skepticism. Starting with a version of the traditional argument that we know nothing about the external world, Unger plunges deeper into skeptical waters by next arguing that there is at most hardly anything which we know to be so; and he scarcely pauses before proceeding to defend the stronger conclusion of ‘universal ignorance,’ the thesis that nobody ever knows anything to be the case. I view Unger's thesis and the arguments that led him to it as a challenge to be overcome, not by an appeal to dogmatism - which Unger sees as the only alternative to skepticism - but by recourse to hard-biting arguments of the sort in which Unger himself puts his faith. In what follows I shall attempt to restate Unger's three main skeptical arguments with a view to showing that their bite is not nearly so hard as he imagines.

Bredo C. Johnsen1 misconceives my strictures concerning acceptance of the following principle : If A both knows that p and knows that p entails q, then A can come to know that q.Johnsen seems unaware that my criticism was intended to apply only after is made to appear in its most plausible light; that is, only after its consequent is interpreted as: ’It is logically possible for A to know that q.’ Without this interpretation might be dismissed simply on the grounds that A suffers from some physical or psychological disability that prevents him from drawing inferences from what he knows.Properly interpreted, remains acceptable as long as the propositions substituted for p and q are such that it is at least logically possible for A to get evidence enough to make them known. Agreement on this point is itself enough to render Johnsen's own examples irrelevant. For instance, even though it may be physically impossible for A to get adequate evidence that in the constellation Andromeda there is a planet intermediate in size between Venus and Earth, the foregoing is still a fit substitution instance for q; but since such a q does not suffice to falsify the consequent of, it does nothing to generate any skeptical argument, either.