ABSTRACT
Personal existence, the existence of ideas, of consciousness, of beliefs—these look equally primordial. Each seems to presuppose one or more of the others; and yet each in turn may be assigned with some plausibility as the basis of the others. We have no other guarantee for the reality of consciousness, of sensations, of personal existence ; we have no other guarantee for any axiom ; we have no other guarantee for any step in a demonstration. Hence, as being taken for granted in every act of the understanding, it must be regarded as the Universal Postulate. An appeal to this Universal Postulate as an absolute warrant for any conviction may still be objected to, on the ground that, as it has on past occasions proved an insufficient warrant, it may prove so again. Beliefs that once were shown by the inconceivableness of their negations to invariably exist, have since been found untrue.
