Nature is what we know. We do not know the gods of religions. And nature is not kind, or merciful, or loving. If God made me - the fabled God of the three qualities of which I spoke: mercy, kindness, love - He also made the fish I catch and eat. And where do His mercy, kindness, and love for that fish come in? No; nature made us - nature did it all - not the gods of the religions.

I am long on ideas, but short on time. I expect to live to be only about a hundred.

I never perfected an invention that I did not think about in terms of the service it might give others... I find out what the world needs, then I proceed to invent.

I've realized that most of my best ideas have followed a good night's sleep.

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.

Direct thought is not an attribute of feminity. In this, women are now centuries behind man.

Show me a thoroughly satisfied man - and I will show you a failure.