is discovered and genera are constituted. But we relegate nothing to the unconscious, for the very simple reason that it is not, in our opinion, an effort of a psychological nature which here disengages similarity; this similarity acts objectively like a force, and provokes reactions that are identical in virtue of the purely physical law which requires that the same general effects should follow the same profound causes. Hydrochloric acid always acts in the same way upon carbonate of lime—whether in the form of marble or of chalk—yet we do not say that the acid perceives in the various species the characteristic features of the genus. Now there is no essential difference between the process by which this acid picks out from the salt its base, and the act of the plant which invariably extracts from the most diverse soils those elements that serve to nourish it. Make one more step; imagine a rudimentary consciousness such as that of an amoeba in a drop of water: it will be sensible of the resemblance, and not of the difference, in the various organic substances which it can assimilate. In short, we can follow from the mineral to the plant, from the plant to the simplest conscious beings, from the animal to man, the progress of the operation by which things and beings seize from out their surroundings that which attracts them, that which interests them practically, without needing any effort of abstraction, simply because the rest of their surroundings takes no hold upon
