We have said that those objects which cannot be incorporated into the one space which the understanding envisages are relegated to another sphere called imagination. We reach here a most important corollary. As material objects, making a single system which fills space and evolves in time, are conceived by abstraction from the flux of sensuous experience, so, _pari passu_, the rest of experience, with all its other outgrowths and concretions, falls out with the physical world and forms the sphere of mind, the sphere of memory, fancy, and the passions. We have in this discrimination the _genesis of mind_, not of course in the transcendental sense in which the word mind is extended to mean the sum total and mere fact of existence—for mind, so taken, can have no origin and indeed no specific meaning—but the genesis of mind as a determinate form of being, a distinguishable part of the universe known to experience and discourse, the mind that unravels itself in meditation, inhabits animal bodies, and is studied in psychology. Mind, in this proper sense of the word, is the residue of existence, the leavings, so to speak, and parings of experience when the material world has been cut out of the whole cloth. Reflection underlines in the chaotic continuum of sense and longing those aspects that have practical significance; it selects the efficacious ingredients in the world. The trustworthy object which is thus retained in thought, the complex of connected events, is nature, and though so intelligible an object is not soon nor vulgarly recognised, because human reflection is perturbed and halting, yet every forward step in scientific and practical knowledge is a step toward its clearer definition. At first much parasitic matter clings to that dynamic skeleton. Nature is drawn like a sponge heavy and dripping from the waters of sentience. It is soaked with inefficacious passions and overlaid with idle accretions. Nature, in a word, is at first conceived mythically, dramatically, and retains much of the unintelligible, sporadic habit of animal experience itself. But as attention awakes and discrimination, practically inspired, grows firm and stable, irrelevant qualities are stripped off, and the mechanical process, the efficacious infallible order, is clearly disclosed beneath. Meantime the incidental effects, the “secondary qualities,” are relegated to a personal inconsequential region; they constitute the realm of appearance, the realm of mind. [Sidenote: Ghostly character of mind.]