be in favour of the hypothesis which finds in perception something which is entirely absent from memory, a reality intuitively grasped. Thus the problem of memory is in very truth a privileged problem, in that it must lead to the psychological verification of two theses which appear to be insusceptible of proof, and of which the second, being of a metaphysical order, appears to go far beyond the borders of psychology.
The road which we have to follow, then, lies clear before us. We shall first pass in review evidences of various kinds borrowed from normal and from pathological psychology, by which philosophers might hold themselves justified in maintaining a physical explanation of memory. This examination must needs be minute or it would be useless. Keeping as close as possible to facts, we must seek to discover where, in the operations of memory, the office of the body begins, and where it ends. And should we, in the course of this enquiry, find confirmation of our own hypothesis, we shall not hesitate to go further and, considering in itself the elementary work of the mind, complete the theory thereby sketched out, of the relation of spirit with matter.
