The very first thing an executive must have is a fine memory. Of course it does not follow that a man with a fine memory is necessarily a fine executive. But if he has the memory he has the first qualification, and if he has not the memory nothing else matters.

Of the 200 light bulbs that didn't work, every failure told me something that I was able to incorporate into the next attempt.

There seems to be no limit to which some men will go to avoid the labor of thinking. Thinking is hard work.

I never did anything worth doing by accident, nor did any of my inventions come indirectly through accident, except the phonograph. No, when I have, fully decided that a result is worth getting, I go about it, and make trial after trial, until it comes.

Vision without execution is delusion.

Maturity is often more absurd than youth and very frequently is most unjust to youth.

I am afraid of radium and polonium ... I don't want to monkey with them.