Let us, for the sake of argument, concede that the manifestations upon which the Spiritists found their claims are genuine: that they are or can be produced without fraud; and let us then enquire in what respect our means for the conversion of the sceptic are improved. In the first place we find that all the manifestations--be their cause what it may--can occur only on the physical plane. However much the origin of the phenomena may perplex us, the phenomena themselves must be purely material, in so far as they are perceptible at all. "Raps" are audible according to the same laws of vibration as other sounds: the tilting table is simply a material body displaced by an adequate agency; the materialized hand or face is nothing but physical substance assuming form. Plainly, therefore, we have as much right to ascribe a spiritual source to such phenomena as we have to ascribe a spiritual source to the ordinary phenomena of nature, such as a tree or a man's body,--just as much right--and no more! Consequently, we are no nearer converting our sceptic than we were at the outset. He admits the physical manifestation: there is no intrinsic novelty about that: but when we proceed to argue that the manifestations are wrought by spirits, he points out to us that this is sheer assumption on our part. "I have not seen a spirit," he says: "I have not heard one; I have not felt one; nor is it possible that my bodily senses should perceive anything that is not at least as physical as they are. I have witnessed certain transactions effected by means unknown to me--possibly by the action of a natural law not yet fully expounded by science. If there was anything spiritual in the affair, it has not been manifest to my apprehension: and I must decline to lend my countenance to any such pretensions."