The Principle that the _esse_ of matter necessarily involves _percipi_, and its correlative Principle that there is not any other substance than Spirit, which is thus the indispensable factor of all reality, both lead on to the more obviously practical Principle—that the material world, _per se_, is wholly powerless, and that all changes in Nature are the immediate issue of the agency of Spirit (sect. 25-27). Concrete power, like concrete substance, is essentially spiritual. To be satisfied that the whole natural world is only the passive instrument and expression of Spiritual Power we are asked to analyse the sensuous data of experience. We can find no reason for attributing inherent power to any of the phenomena and phenomenal things that are presented to our senses, or for supposing that _they_ can be active causes, either of the changes that are continuously in progress among themselves, or of the feelings, perceptions, and volitions of which spiritual beings are conscious. We find the ideas or phenomena that pass in procession before our senses related to one another as signs to their meanings, in a cosmical order that virtually makes the material world a language and a prophecy: but this cosmical procession is not found to originate in the ideas or phenomena themselves, and there is reason for supposing it to be maintained by ever-living Spirit, which thus not only substantiates the things of sense, but explains their laws of motion and their movements. Yet the universe of reality is not exclusively One Spirit. Experience contradicts the supposition. I find on trial that my personal power to produce changes in the ideas or phenomena which my senses present to me is a limited power (sect. 28-33). I can make and unmake my own fancies, but I cannot with like freedom make and unmake presentations of sense. When in daylight I open my eyes, it is not in my power to determine whether I shall see or not; nor is it in my power to determine what objects I shall see. The cosmical order of sense-phenomena is independent of my will. When I employ my senses, I find myself always confronted by sensible signs of perfect Reason and omnipresent Will. But I also awake in the faith that I am an individual person. And the sense-symbolism of which the material world consists, while it keeps me in constant and immediate relation to the Universal Spirit, whose language it is, keeps me likewise in intercourse with other persons, akin to myself, who are signified to me by their overt actions and articulate words, which enter into my sensuous experience. Sense-given phenomena thus, among their other instrumental offices, are the medium of communication between human beings, who by this means can find companions, and make signs to them. So while, at _our_ highest point of view, Nature is Spirit, experience shews that there is room in the universe for a plurality of persons, individual, and in a measure free or morally responsible.