in Thoreau’s Journal:

As a nation the people never utter one great and healthy word— From side all nations present only the symptoms of disease…In society you will not find health but in nature— You must converse much with the field and woods if you would imbibe such health into your mind and spirit as you covet for your body….I should like to keep some books of natural history always by me as a sort of elixir—the reading of which would restore the tone of my system—and secure me true and cheerful views of life….To the soul that contemplates some trait of natural beauty no harm nor disappointment can come. The doctrines of despair—of spiritual or political servitude—no priestcraft nor tyranny—was ever taught by such as drank in the harmony of nature.