Nature as a discipline — a means of arriving at comprehension — forms the subject of Chapter V, "Discipline." All of nature serves to educate man through both the rational, logical "Understanding" and the intuitive, mystical "Reason." Through the more rational understanding, we constantly learn lessons about the similarities and differences between objects, about reality and unreality, about order, arrangement, progression, and combination. The ultimate result of such lessons is common sense. Emerson offers property and debt as materially based examples that teach necessary lessons through the understanding, and space and time as demonstrations of particularity and individuality, through which "we may know that things are not huddled and lumped, but sundered and individual." Each object has its own particular use, and through the understanding we know that it cannot be converted to other uses to which it is not fitted. The wise man recognizes the innate properties of objects and men, and the differences, gradations, and similarities among the manifold natural expressions. The practical arts and sciences make use of this wisdom. But as man progressively grasps the basic physical laws, he comes closer to understanding the laws of creation, and limiting concepts such as space and time lose their significance in his vision of the larger picture. Emerson emphasizes the place of human will — the expression of human power — in harnessing nature. Nature is made to serve man. We take what is useful from it in forming a sense of the universe, giving greater or lesser weight to particular aspects to suit our purposes, even framing nature according to our own image of it. Emerson goes on to discuss how intuitive reason provides insight into the ethical and spiritual meanings behind nature. "All things are moral," he proclaims, and therefore every aspect of nature conveys "the laws of right and wrong."
Nature thus forms the proper basis for religion and ethics. Moreover, the uses of particular facets of nature as described in "Commodity" do not exhaust the lessons these aspects can teach; men may progress to perception of their higher meaning as well. Emerson depicts moral law as lying at the center of the circle of nature and radiating to the circumference. He asserts that man is particularly susceptible to the moral meaning of nature, and returns to the unity of all of nature's particulars. Each object is a microcosm of the universe. Through analogies and resemblances between various expressions of nature, we perceive "its source in Universal Spirit." Moreover, we apprehend universal order through thought — through our grasp of the relationship between particular universal truths, which are related to all other universal truths. Emerson builds upon his circle imagery to suggest the all-encompassing quality of universal truth and the way it may be approached through all of its particulars. Unity is even more apparent in action than in thought, which is expressed only imperfectly through language. Action, on the other hand, as "the perfection and publication of thought," expresses thought more directly. Because words and conscious actions are uniquely human attributes, Emerson holds humanity up as the pinnacle of nature, "incomparably the richest informations of the power and order that lie at the heart of things." Each human example is a point of access into the universal spirit. As an expression of nature, humanity, too, has its educational use in the progression toward understanding higher truth.
