  Is such a view coherent? Here it is appropriate to ask the skeptic what kind of justification she is seeking. The question returns us to the problem of PNC being a first principle for which there is no ordinary proof. Is it possible to act as if one has certain beliefs even though one does not? Here the skeptic owes the non-skeptic some account of “as-if belief” that differs from actual belief. If this is to act following “how things appear to one”, Aristotle is justified in asking whether they can even appear to be F and not F to the same human being at the same time. “As-if belief” may commit one to PNC just as much as actual belief does.