If he [Thomas Edison] had a needle to find in a haystack, he would not stop to reason where it was most likely to be, but would proceed at once with the feverish diligence of a bee, to examine straw after straw until he found the object of his search. ... [J]ust a little theory and calculation would have saved him ninety percent of his labor.

Money does not represent such a value as men have placed upon it. All my money has been invested into experiments with which I have made new discoveries enabling mankind to have a little easier life.

The progressive development of man is vitally dependent on invention.

When I get an idea I start at once building it up in my imagination. I change the construction, make improvements and operate the device in my mind. It is absolutely immaterial to me whether I run my turbine in my thought or test it in my shop. I even note if it is out of balance.

All that was great in the past was ridiculed, condemned, combated, suppressed — only to emerge all the more powerfully, all the more triumphantly from the struggle.

Of all things I liked books best.

My mother understood human nature better and never chided. She knew that a man cannot be saved from his own foolishness or vice by someone else's efforts or protests, but only by the use of his own will.