"Keep your eyes on the stars, and your feet on the ground."

"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."

"Spend and be spent."

"If there is not the war, you don't get the great general; if there is not a great occasion, you don't get a great statesman; if Lincoln had lived in a time of peace, no one would have known his name."

"To announce that there must be no criticism of the president, right or wrong - is not only unpatriotic and servile, but is morally treasonable to the American public."

"While my interest in natural history has added very little to my sum of achievement, it has added immeasurably to my sum of enjoyment in life."

"Fraud is the ready minister of injustice."

"Honor has not to be won; it must only not be lost."

"Do not wait for the last judgment. It takes place every day."

"First comes thought; then organization of that thought, into ideas and plans; then transformation of those plans into reality. The beginning, as you will observe, is in your imagination."

"Happiness, noun. An agreeable sensation arising from contemplating the misery of another."

"In individuals, insanity is rare; but in groups, parties, nations, and epochs it is the rule."