[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.

How many thorns of human nature - hard, sharp, lifeless protuberances that tear and wound us, narrow prejudices, bristling conceits that repel and disgust us - are arrested developments, calcified tendencies, buds of promise that should have lifted a branch up into the sunny day with fruit; and flowers to delight the heart of men, but now all grown hard, petrified, for want of culture and a congenial soil and climate.

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.

Look up at the miracle of the falling snow,—the air a dizzy maze of whirling, eddying flakes, noiselessly transforming the world, the exquisite crystals dropping in ditch and gutter, and disguising in the same suit of spotless livery all objects upon which they fall.

Nature teaches more than she preaches. There are no sermons in stones. It is easier to get a spark out of a stone than a moral.

Certainly in the United States, you have a constituency in the form of the weapons laboratories, and you also have the branches of the armed services that are involved with nuclear weapons deployment, especially the naval submarine operations and also the air force's land-based ICBM operations. So they have a big lobby in Washington.

One resolution I have made, and try always to keep, is this: ‘To rise above little things’.