The three things that are most essential to achievement are common sense, hard work and stick-to-it-iv-ness.

I am long on ideas, but short on time. I expect to live to be only about a hundred.

Your worth consists in what you are and not in what you have.

Our greatest weakness lies in giving up.

Today, I am wondering what would have happened to me by now, if, fifty years ago, some fluent talker had converted me to the theory of the eight-hour day and convinced me that it was not fair to my fellow-workers to put forth my best efforts in my work? I am glad that the eight-hour day had not been invented when I was a young man. If my life had been made up of eight-hour days, I don't believe I could have accomplished a great deal.

Invention is 1% inspiration and 99% perspiration

I have not failed. I have successfully discovered 1200 ideas that don't work.