I never once failed at making a light bulb. I just found out 99 ways not to make one.

I have better use for my brain than to poison it with alcohol. To put alcohol in the human brain is like putting sand in the bearings of an engine.

I have not failed 10,000 times. I have succeeded in proving that those 10,000 ways will not work.

It is very different to make a practical system and to introduce it. A few experiments in the laboratory would prove the practicability of system long before it could be brought into general use. You can take a pipe and put a little coal in it, close it up, heat it and light the gas that comes out of the stem, but that is not introducing gas lighting. I'll bet that if it were discovered to-morrow in New York that gas could be made out of coal it would be at least five years before the system would be in general use.

Genius is 1 percent inspiration, 99 percent perspiration.

To those searching for truth -- not the truth of dogma and darkness but the truth brought by reason, search, examination, and inquiry, discipline is required. For faith, as well intentioned as it may be, must be built on facts, not fiction -- faith in fiction is a damnable false hope.

The United States, and other advanced nations, will someday be able to produce instruments of death so terrible the world will be in abject terror of itself and its ability to end civilization.... Such war-making weapons should be developed - but only for purposes of discovery and experimentation