 John’s moderate skepticism accepts that there are three reliable foundations for knowledge: faith, reason, and the senses (PC: 153–56). Thus, it does not behoove the philosopher to question his faith in the existence of God, nor the certainty of some mathematical postulates, nor a number of other first principles which “one is not permitted to doubt, except for those who are occupied by the labors of not knowing anything” (PC: 154). Though it might seem that John’s skepticism is not so very skeptical after all, he generates a lengthy list of