We agree in all the main positions with Professor Münsterberg, but in the last mentioned point we disagree. Professor Münsterberg limits psychical states or feelings to states of consciousness without considering that there are subconscious and even unconscious feelings. By consciousness we understand those feelings alone which are concentrated so as to be connected with the ego, i. e. the present centre of consciousness. We assume that even the spinal ganglions of the brainless frog are feeling if the skin is irritated, but this feeling can never become conscious, it can no more be telegraphed to the central station so as to become co-ordinated with other feelings which are registered in the brain. The objection may be raised, We do not know whether the ganglion is feeling; and I should answer, I call feeling anything that is of the same nature as the elements of which consciousness consists, and we have all reasons to assume that there is such an elementary psychical accompaniment of the ganglionic irritations, and that consciousness rises from many such elements through their co-ordinate combination in the brain. Isolated feelings are never conscious, and consciousness is a co-operative system of feeling. This distinction between consciousness and feeling is a mere matter of terminology. If we find another terminology more practical we are willing to surrender ours. Yet such a distinction between consciousness and feeling seems to be necessary for a proper description of the psychical facts. The assumption of subconscious states and even of unconscious feelings is a great help in explaining the phenomena of consciousness. But unless we are grossly mistaken, our disagreement is merely apparent, for Professor Münsterberg, rejecting the idea of a psychological explanation, believes in the parallelism of psychical and physical phenomena. “The physical acts” (he says on p. 125) “reducible to mechanical axioms can be explained through causation, the psychical acts follow one another without inner necessity. If we connect both, we are enabled to transfer the necessity-connection of the physical upon the psychical and offer thus an explanation where otherwise description only was possible.” But in doing this, have we not supplemented those psychical elements which appear as conscious states by other psychical elements which have not entered into that combination which makes them actually conscious? It is an hypothetical addition for the sake of explanation, a _Hilfsconstruction_ just as much as the supposition of the existence of atoms or electric currents or other physical phenomena which are not directly observed, but indirectly in their effects only.