Regarding the views of Emerson and Thoreau, how is transcendentalism related to the wilderness?
Transcendentalism is a philosophy of universal harmony, that everything in the universe is connected spiritually. Humans have the ability to connect with the larger spiritual universe by a process of self-discovery in which a person attunes the self with the universe; this must be a personal process, not guided by organizations or leaders. Embracing Nature, with wild animals and instinct, is part of that process. Both Emerson and Thoreau saw nature as an integral part of their own self-discovery; Emerson, in a lecture, said:
Nature is transcendental, exists primarily, necessarily, ever works and advances, yet takes no thought for the morrow. Man owns the dignity of the life which throbs around him in chemistry, and tree, and animal, and in the involuntary functions of his own body; yet he is balked when he tries to fling himself into this enchanted circle, where all is done without degradation.
(Emerson, "The Transcendentalist," emersoncentral.com)
In other words, while the wilderness is instinctively in a state of transcendentalism, Man must work at it, because man is too-much able to think about consequences and morality. Nature "exists primarily" since there is no sentient thought in it; animals and plants move according to their "life chemistry" which operates regardless of their personal thought or intent. Instead, they are driven by their instinctive understanding of the larger universe and their own place in it. Man, in contrast, is constantly trying to change and alter his place in the universe; mankind is a thinking animal and can wonder, invent, and define without knowledge or care of the outside world. For Emerson and others, Man should make the effort to not only understand Nature, but to embrace it as "primal" instead of trying to alter it. Only after a person has discovered his or her own "self" as defined and compared with the larger universe can the process of transcending ordinary life begin.