Thoreau called himself a mystic, and a transcendentalist, and a natural philosopher to boot. But the least of these was the natural philosopher. He did not have the philosophic mind, nor the scientific mind; he did not inquire into the reason of things, nor the meaning of things; in fact, had no disinterested interest in the universe apart from himself. He was too personal and illogical for a philosopher. The scientific interpretation of things did not interest him at all. He was interested in things only so far as they related to Henry Thoreau. He interpreted Nature entirely in the light of his own idiosyncrasies.
Science goes its own way in spite of our likes and dislikes, but Thoreau's likes and dislikes determined everything for him. He was stoical, but not philosophical. His intellect had no free play outside his individual predilection. Truth as philosophers use the term, was not his quest but truth made in Concord.
Thoreau writes that when he was once asked by the Association for the Advancement of Science what branch of science he was especially interested in, he did not reply because he did not want to make himself the laughing-stock of the scientific community, which did not believe in a science which deals with the higher law--his higher law, which bears the stamp of Henry Thoreau.
He was an individualist of the most pronounced type. The penalty of this type of mind is narrowness; the advantage is the personal flavor imparted to the written page. Thoreau's books contain plenty of the pepper and salt of character and contrariness; even their savor of whim and prejudice adds to their literary tang. When his individualism becomes aggressive egotism, as often happens, it is irritating; but when it gives only that pungent and personal flavor which pervades much of "Walden," it is very welcome.
Thoreau's critics justly aver that he severely arraigns his countrymen because they are not all Thoreaus--that they do not desert their farms and desks and shops and take to the woods. What unmeasured contempt he pours out upon the lives and ambitions of most of them! Need a nature-lover, it is urged, necessarily be a man-hater? Is not man a part of nature?--averaging up quite as good as the total scheme of things out of which he came? Cannot his vices and shortcomings be matched by a thousand cruel and abortive things in the fields and the woods? The fountain cannot rise above its source, and man is as good as is the nature out of which he came, and of which he is a part. Most of Thoreau's harsh judgments upon his neighbors and countrymen are only his extreme individualism gone to seed.