have already become acquainted with Haeckel's philosophy of mind; let us here simply accentuate the phases of it which do not agree with the fundamental principles. Soul life is the sum-total of vital phenomena which are all bound to a material substrate, conditioned by physiological functions. Soul is a collective term for the sum-total of the psychic functions of the plasm. 'Soul' is a collective term for a sum of brain functions, which are, like all life-activities, conditioned by physical and chemical processes. Soul life is unconscious until we reach the higher animals where it becomes conscious. Consciousness, however, is merely a development from the lower forms of psychic life and, like these, a function of physiological processes. It is dependent on the chemical changes of the brain; it is a physiological problem and as such solved by physics and chemistry. The sentient energy with which we began, which was at least equal in dignity with matter at the outset, and which assumed importance enough in the scheme to cause the matter to move, to attract and to repel, is now made the function of matter. Matter is the substrate, the substance; soul or mind the function of matter, housed in the latter and dependent upon it. Matter has become king; energy or mind its slave. Our so-called pure monism has changed into materialism, if not in the sense that it reduces everything, energy included, to matter and motion, at least in the sense that it makes this energy an attribute, a function of matter.
Besides the inconsistencies which we have noticed all along the line, there are difficulties in the system upon some of which we have already lightly touched. The continuous substance filling infinite space and endowed with infinite energy must do something if a cosmos is to be formed. It begins to differentiate and to form atoms. We are told why it does so: it has the unconscious impulse to do so, it is endowed with the properties of love and hate, which are only different names for attraction and repulsion. Why the infinite substance should want to do all this, we are left to figure out for ourselves. It is worth noting here, however, that Haeckel introduces the conception of purposive impulse into his explanation of the cosmos, an unconscious impulse or striving, it is true, but still a force attempting to account for the movements of the atoms. He does not therefore repudiate the teleological explanation in toto, as he claims to do, but only conscious teleology.
But in spite of all this the theory does not explain how these animated atoms floating in the ether can produce a world. We have here the same old difficulty which was presented to us by the first Greek atomists. In fact it is somewhat increased. Each pyknatom acts spontaneously; it is not a dead thing buffeted into place by other dead things, but a living thing that seeks its place, that strives to be united with other atoms which also strive, and their harmonious strivings give us a world. This is certainly a mystery of mysteries. Why the little atoms
