We shall have no better conditions in the future if we are satisfied with all those which we have at present.

The best thinking has been done in solitude. The worst has been done in turmoil.

If I had not had so much ambition and not tried to do so many things, I probably would have been happier, but less useful.

Nature is truly wonderful. Only man is truly foul.

Results! Why, man, I have gotten a lot of results. I know several thousand things that won't work.

There seems to be no limit to which some men will go to avoid the labor of thinking. Thinking is hard work.

When you have exhausted all possibilities, remember this - you haven't.