“There is a certain plaintiveness in this catalog of Thoreau’s, a romantic’s lament for the pristine world of an earlier and now lost time. The myth of a fallen humanity in a fallen world is never far beneath the surface in Thoreau’s writing, and nowhere is this more visible than in his descriptions of past landscapes.”

Here Cronon identifies a primary theme of the American Romantic period in literature, which highlights the natural world and associates the care of the environment with spirituality. For most American writers during this period of about 1830–1860, ideas that tied the fate of man’s soul to the environment around him were central to self-expression, self-discovery, and self-reliance.

“It is important that we answer this question of Thoreau’s carefully: how did the ‘nature’ of New England change with the coming of the Europeans, and can we reasonably speak of its changes in terms of maiming and imperfection? There is nothing new to the observation that European settlement transformed the American landscape. Long before Thoreau, naturalists and historians alike were commenting on the process which was converting ‘wilderness’ into a land of European agricultural settlement.”

Cronon wants to avoid the pitfall of lamenting the ruination of a fallen, previously pristine Eden by European settlement without applying the logic of historical research to determining the causes of that change. That settlement changes the landscape cannot be denied, but Cronon is more interested in the question of how the landscape was altered and by what means or practices it was transformed.

“The task before us is not only to describe the ecological changes that took place in New England but to determine what it was about Indians and colonists—in their relations both to nature and to each other—that brought those changes about.”

This passage defines the main idea, or thesis, of Cronon’s work.