In this fourth section, Emerson discusses the relationship between nature and language: Words represent objects in nature; these individual objects signify spiritual realities; and nature symbolizes spirituality.
To explain how words represent natural objects, Emerson uses etymology — the origin and development of words — to illustrate that abstract terms are derived from words for physical things. According to this view, which has been discredited by modern linguists, language is a series of metaphors, symbols representing other things. For example, at one time spirit evoked the word wind; we use the word heart to express emotion; and head is often synonymous with reason. These meanings are incorporated into our language to such a great extent that we forget the ways that words and their meanings originate.
Nature, as the interpreter between people, supplies the language that people use to communicate with. A river, for example, expresses the passage of time, and the seasons of the year correspond to the stages of human growth. Emerson naively assumes that these correspondences are universal and understood by all human beings. For example, he says that all people recognize that light and dark figuratively express knowledge and ignorance, respectively. This theme of universal understanding is emphasized further when he claims that each individual shares a universal soul linking that person to all others, as well as to the whole of nature.
