There is superstition in science quite as much as there is superstition in theology, and it is all the more dangerous because those suffering from it are profoundly convinced that they are freeing themselves from all superstition.

I don't pity any man who does hard work worth doing. I admire him. I pity the creature who does not work, at whichever end of the social scale he may regard himself as being.

Unrestrained greed means the ruin of the great woods and the drying up of the sources of the rivers.

Burning fossil fuels is like breaking up the furniture to feed the fireplace because it's easier than going out to the woodpile.

Speak softly and carry a big stick; you will go far.

It behooves every man to remember that the work of the critic is of altogether secondary importance, and that, in the end, progress is accomplished by the man who does things.

To have acted otherwise ... would have been the betrayal of the interests of the United States.