In Chapter IV, "Language," Emerson explores nature's service to man as a vehicle for thought. He first states that words represent particular facts in nature, which exists in part to give us language to express ourselves. He suggests that all words, even those conveying intellectual and moral meaning, can be etymologically traced back to roots originally attached to material objects or their qualities. (Although this theory would not be supported by the modern study of linguistics, Emerson was not alone among his contemporaries in subscribing to it.) Over time, we have lost a sense of the particular connection of the first language to the natural world, but children and primitive people retain it to some extent. Not only are words symbolic, Emerson continues, but the natural objects that they represent are symbolic of particular spiritual states. Human intellectual processes are, of necessity, expressed through language, which in its primal form was integrally connected to nature. Emerson asserts that there is universal understanding of the relationship between natural imagery and human thought. An all-encompassing universal soul underlies individual life. "Reason" (intuitive understanding) affords access to the universal soul through the natural symbols of spirit provided by language. In language, God is, in a very real sense, accessible to all men. In his unique capacity to perceive the connectedness of everything in the universe, man enjoys a central position. Man cannot be understood without nature, nor nature without man. In its origin, language was pure poetry, and clearly conveyed the relationship between material symbol and spiritual meaning. Emerson states that the same symbols form the original elements of all languages. And the moving power of idiomatic language and of the strong speech of simple men reminds us of the first dependence of language upon nature. Modern man's ability to express himself effectively requires simplicity, love of truth, and desire to communicate efficiently. But because we have lost the sense of its origins, language has been corrupted. The man who speaks with passion or in images — like the poet or orator who maintains a vital connection with nature — expresses the workings of God.
Finally, Emerson develops the idea that the whole of nature — not just its particulate verbal expressions — symbolizes spiritual reality and offers insight into the universal. He writes of all nature as a metaphor for the human mind, and asserts that there is a one-to-one correspondence between moral and material laws. All men have access to understanding this correspondence and, consequently, to comprehending the laws of the universe. Emerson employs the image of the circle — much-used in Nature — in stating that the visible world is the "terminus or circumference of the invisible world." Visible nature innately possesses a moral and spiritual aspect. Man may grasp the underlying meaning of the physical world by living harmoniously with nature, and by loving truth and virtue. Emerson concludes "Language" by stating that we understand the full meaning of nature by degrees.
