"During all those years of experimentation and research, I never once made a discovery. All my work was deductive, and the results I achieved were those of invention, pure and simple. I would construct a theory and work on its lines until I found it was untenable. Then it would be discarded at once and another theory evolved. This was the only possible way for me to work out the problem. … I speak without exaggeration when I say that I have constructed 3,000 different theories in connection with the electric light, each one of them reasonable and apparently likely to be true. Yet only in two cases did my experiments prove the truth of my theory. My chief difficulty was in constructing the carbon filament. . . . Every quarter of the globe was ransacked by my agents, and all sorts of the queerest materials used, until finally the shred of bamboo, now utilized by us, was settled upon."

“: I consider Paine our greatest political thinker. As we have not advanced, and perhaps never shall advance, beyond the Declaration and Constitution, so Paine has had no successors who extended his principles. --The Philosophy of Paine”

“If we did all the things we are capable of doing, we would literally astound ourselves.”

“To Monsieur Eiffel the Engineer, the brave builder of so gigantic and original a specimen of modern Engineering from one who has the greatest respect and admiration for all Engineers including the Great Engineer the Bon Dieu.”

“If our nation can issue a dollar bond, it can issue a dollar bill. The element that makes the bond good, makes the bill good, also. The difference between the bond and the bill is the bond lets money brokers collect twice the amount of the bond and an additional 20%, whereas the currency pays nobody but those who contribute directly in some useful way. … It is absurd to say our country can issue $30 million in bonds and not $30 million in currency. Both are promises to pay, but one promise fattens the usurers and the other helps the people.”

“X-rays ... I am afraid of them. I stopped experimenting with them two years ago, when I came near to losing my eyesight and Dally, my assistant practically lost the use of both of his arms.”

“Edison, Thomas A., "The Philosophy of Thomas Paine”