Laying out the problem that he will attempt to solve in the essay, Emerson states that our energy and excitement in creating something new has been lost because we try to understand the world around us by using only theories and histories about nature rather than personally observing it. One solution to this problem involves our casting off impersonal theories or descriptions that distance us from nature and ourselves; afterwards, we can reexamine the actual thing that we are a part of — namely, nature. Direct experience with nature is best because it provides better insight into the contemporary world than does the historian's teachings or the scientist's theories.
Emerson's discarding traditional ways of viewing the world indicates the importance that progress will play in the essay. Note that the worm/man relationship in the 1849 epigraphic poem contains verbs — " striving" and "mounts" — that connote the idea of progress. But Emerson also draws attention to the backward steps we too readily think of as progressive. He characterizes these steps as groping "among the dry bones of the past," and he quickly moves from this notion of a stagnant death to one of a revitalized future in which original thoughts reign.
In order to help us focus more clearly on nature, Emerson distinguishes nature from art. Art, he says, is natural objects or materials that we alter for our own purposes — for example, a statue or a picture. That said, however, this distinction is relatively inconsequential to Emerson.
The introduction ends by defining nature as all that is external to ourselves — all that is "not me," including our own bodies.