That Thoreau like Emerson accepts Nature as an enigma is the attitude of Zen. Such an attitude clearly is conveyed in his Walden and A Week. Thoreau considered himself first and always naturalist or better the poet naturalist, not in empirical sense of collecting mere facts, but in a mystic way.
His interest in the flora and fauna of his beloved Concord was not so much scientific as poetic. He would simply fall in love with a scrub oak, or a woodchuck or a pinxter flower or the mysterious night warbler. This love, this enthusiasm for nature flowed over into his writings, making him not only the first outstanding nature writer but also the greatest in American Literature. He was a poet and mystic, not a systematist or taxonomist.
In 1853, when the Secretary of the Association for the Advancement of Science requested him to specify the branch of science in which he was specially interested, Thoreau bluntly recorded, “The fact is I am a mystic, a transcendentalist, and a natural philosopher to boot.” At times, he was for more than a naturalist. He was interested in life, life of all kinds, and its meaning and significance. For him, like a Zen, every thing in Nature is an embodiment of infinity and endowed with profundity.
Like Zen, he approached Nature on its own terms, humanized it without indulging in the pathetic fallacy. Through his eyes he saw Nature clearly. In Zen Buddhism Nature plays a crucial role, it is indispensable for self-realization, inseparable from man’s life. Nature forms an important part of man’s background. Thoreau too believes strongly that Nature is essential to man. He says that man must derive his strength from his contact with the earth and with Nature. If man is deprived of that contact, he becomes weak physically, spiritually and morally. Communion with Nature constantly makes him strong spiritually.
Mystics of all times and all religions have established this fundamental inalienable link by living close to Nature, or almost in solitude in Nature. Snap these ties, man is empty. Nature serves as a means to realize the Great Self. She is the treasure house of wisdom. Thoreau in every respect conformed to this principle laid down by sages and saints.