The finer and more delicate feelings cannot be gauged. But even though the alleged parallelism were entirely demonstrated, the immediate and pertinent question would still remain, Who or what is the investigator? Is it an ego, a thinking self? or is it only a complex of vibrations or mechanical impressions bound together in a particular body which, for convenience, is called an ego? Are the so-called entities--personality, consciousness, self--but symbols, as Professor Mach says, useful in so far as they help us to express our physical sensations, but which with further research must be pronounced illusions?[1] Monistic naturalism, which would explain all psychical experiences in terms of cerebral action, must not be allowed to arrogate to itself powers which it does not possess, and quietly brush {86} aside facts which do not fit into its system. The moral sanctions so universally and deeply rooted in the consciousness of mankind, the feelings of responsibility, of guilt and regret; the soul's fidelities and heroisms, its hopes and fears, its aims and ideals--the poetry, art, and religion that have made man what he is, all that has contributed to the uplifting of the world--are, to say the least, unaccounted for, if it must be held that 'man is born in chains.' Primary facts must not be surrendered nor ultimate experiences sacrificed in the interests of theoretic simplicity. In the recent anti-metaphysical movement of Germany, of which Haeckel, Avenarius, Oswald and Mach are representatives, there is presented the final conflict. It is not freedom of will only that is at stake, it is the very existence of a spiritual world. 'Es ist der Kampf um die Seele.'[2] If the world forms a closed and 'given' system in which every particular is determined completely by its position in the whole, then there can be no place for spontaneity, initiative, creation, which all investigation shows to be the distinctive feature in human progress and upward movement. So far from its being true that the world makes man, it would be nearer the truth to say that man makes the world. A 'given' world can never be primary.[3] There must be a mind behind it. We fall back, therefore, upon the principle which must be postulated in the whole discussion--the unity and self-determining activity of the self-conscious mind. II