If I were to name the three most precious resources of life, I should say books, friends, and nature.

The atmosphere of our time is fast being cleared of the fumes and deadly gases that arose during the carboniferous age of theology.

The secret of happiness is something to do.

One summer day, while I was walking along the country road on the farm where I was born, a section of the stone wall opposite me, and not more than three or four yards distant, suddenly fell down. Amid the general stillness and immobility about me the effect was quite startling. ... It was the sudden summing up of half a century or more of atomic changes in the material of the wall. A grain or two of sand yielded to the pressure of long years, and gravity did the rest.

One of the hardest lessons we have to learn in this life, and one that many persons never learn, is to see the divine, the celestial, the pure, in the common, the near at hand-to see that heaven lies about us here in this world.

A man can fail many times, but he isn't a failure until he begins to blame somebody else.

[Theodore Roosevelt] was a naturalist on the broadest grounds, uniting much technical knowledge with knowledge of the daily lives and habits of all forms of wild life. He probably knew tenfold more natural history than all the presidents who had preceded him, and, I think one is safe in saying, more human history also.