atom-souls, molecule-souls, this hatred and love which are the inner aspects even of the simple facts of attraction and repulsion among the elements, fit better into the nature-philosophy of Empedocles and Anaxagoras than into ours. The main support, indeed the sole support, of this position is that this world of the infinitely little cannot be brought under control as far as its “soul” is concerned. Thus we can impute “a soul” to it without danger. On the other hand, there is a difficulty which made itself felt even in regard to Spinoza’s system. All bodily processes must have psychical processes corresponding to them, said Spinoza. Conversely, all ideas in their turn must have bodily processes. To the system including all bodily processes corresponds the sum-total of psychical processes. This sum-total we call the soul. And in its entirety it is the _idea corporis_. If “soul” were really nothing more than this, the theory of parallelism might be right. But it is more than this. It rises above itself, and becomes also the _idea ideæ_; it is self-consciousness and the consciousness of the ego; it makes its own thought and the laws of it, its feelings and their intensity—its experiences in short—a subject of thought. How does this fit in with parallelism? Wundt himself, the most notable modern champion of parallelism, admits and defines these limits of the parallelistic theory on both sides. Furthermore, the theory of parallelism, notwithstanding its opposition to materialism, must presuppose that localisation of psychical processes of which we have already spoken, and to which all naturalism appeals with so much emphasis. Because of the fact that particular psychical functions seem to be limited to a particular and definable area of the brain-cortex, or to a spot which could be isolated on a particular convolution, it seemed as if naturalism could prove that “soul” was obviously a function of this particular organ or part of an organ. According to the theory of parallelism this does not follow. It would assert: “What in one aspect appears to be a psychical process, appears in another aspect to be a definite physiological process of the brain.” Yet it is clear that in order to gain support for the doctrine of mutual correspondence, parallelism has also the same interest in such localisation. For this is the only method by which it can empirically control its theory. But this whole idea of localisation does not hold good to anything like the extent to which the members of the naturalistic school are wont to assert that it does. In regard to this point, too, there has been considerable disillusioning in recent years. Perhaps all that can be said is, that localisation of psychical processes is a fact analogous to the fact that sight is associated with the optic nerves and hearing with the auditory nerves. Progressive investigation leads more and more clearly to the recognition of a fact which makes localisation comparatively unimportant,