If Understanding is concerned with the knowledge of how objects function in the world, then Reason, the second major point under the heading of Discipline, is the intuition needed to understand those objects. Emerson's definition of Reason is markedly different than ours today. For us, Reason means the process by which we logically and rationally deduce different phenomena; for him, however, Reason is tied to intuiting how nature, which he believes is a moral teacher, offers ethical and spiritual insights. Reason is linked to intuition, Understanding to rationality. Every natural object offers a sermon on some spiritual or divine reality. For example, the fisherman learns firmness, which is morally good, from observing centuries-old, sea-beaten rocks: To be firm about something is a morally correct way of acting and shows to what extent a person will defend what he or she thinks is right.
Emerson then returns to the theme that all things in nature create a single whole. Analogies and resemblances between physical and spiritual realities cause the mind to perceive the universe as a single, organic whole, with each part significant and harmonious. This unity also encompasses relationships between people, whose bodies Emerson regards as nature's most perfect products and the objects that most eloquently embody spiritual truths.
Also important in this section is Emerson's tying together many of the other themes found throughout the essay. For example, the unity of all objects in nature is the single most important ordering mechanism defining our lives. To express this ordering, Emerson likens his belief that every universal truth recalls all other truths to the geometrical shape of a circle, which has no beginning, no end: "It is like a great circle on a sphere, comprising all possible circles; which, however, may be drawn, and comprise it, in like manner." The circle best represents nature's order because all circles have the same form, just as all of nature's truths recall one another.
