would psychology, as we have conceived, it find its occupation gone. There would be no science of psychology to affiliate with the natural sciences; it would have about as much standing in court as a science of augury. "Wo nichts ist hat der Kaiser sein Recht verloren."
The ideal, however, is far from realized. We possess no such astronomical knowledge of the occurrences in the nervous system as is here dreamed of. Our knowledge of the processes on which the elementary forms of psychic life are said to depend is far from certain, exact, and complete; while of the higher forms of mind we have no physiological knowledge worth speaking of, so little indeed as to prompt physiologists themselves to deny the existence of a science of cerebral psychology. "It would of course be a great triumph," Du Bois-Reymond once said, "if we could say that a particular motion of particular atoms takes place in particular ganglionic cells and nerve fibers corresponding to a particular mental process. It would be immensely interesting if we could turn the gaze inward and watch the operations of the brain mechanism that is going on when we are working out a problem in arithmetic, just as we can watch the mechanism in an adding machine, or even if we knew what dancings of atoms of carbon, hydrogen, nitrogen, phosphorus, and other elements corresponded to the joy of musical sensation, what whirlings of such atoms corresponded to the highest pitch of the pleasures of sense, what molecular storms accompanied the maddening pain occasioned by injury to the nervus trigeminus.… At present we do not even know whether only the gray matter or also the white matter of the brain thinks, or whether a definite configuration or a definite movement of brain atoms or molecules corresponds to a particular soul state."
Here we are forced to speak, for the most part, in figures of speech. We do not know what is going on in the brain, we do not even know that all mental states have their physiological counterparts. We can form hypotheses concerning what is happening, but, let it be remembered, these hypotheses cannot be formed without due regard to the thought world which they undertake to explain. If the phenomena of consciousness are
