7. Are There Limits to Knowledge?

Let us examine these real principles a little more closely. The naïve man (naïve realist) regards the objects of external experience as realities. The fact that his hands can grasp these objects, and his eyes see them, is for him sufficient proof of their reality. “Nothing exists that cannot be perceived” is, in fact, the first axiom of the naïve man; and it is held to be equally valid in its converse: “Everything which can be perceived exists.” The best evidence for this assertion is the naïve man's belief in immortality and ghosts. He thinks of the soul as refined material substance which may, in special circumstances, become visible even to the ordinary man (naïve belief in ghosts).