The three great essentials to achieve anything worthwhile are, first, hard work; second, stick-to-itiveness; third, common sense. - Thomas Edison

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.

Restlessness is discontent — and discontent is the first necessity of progress. Show me a thoroughly satisfied man — and I will show you a failure.

He has been called an atheist, but atheist he was not. Paine believed in a supreme intelligence, as representing the idea which other men often express by the name of deity. His Bible was the open face of nature, the broad skies, the green hills. He disbelieved the ancient myths and miracles taught by established creeds. But the attacks on those creeds — or on persons devoted to them — have served to darken his memory, casting a shadow across the closing years of his life. When Theodore Roosevelt termed Tom Paine a "dirty little atheist" he surely spoke from lack of understanding. It was a stricture, an inaccurate charge of the sort that has dimmed the greatness of this eminent American. But the true measure of his stature will yet be appreciated. The torch which he handed on will not be extinguished.