Sometimes I feel that by not marrying, I made too great a sacrifice to my work.

Religion is simply an ideal. It is an ideal force that tends to free the human being from material bonds. I do not believe that matter and energy are interchangeable, any more than are the body and soul. There is just so much matter in the universe and it cannot be destroyed. As I see life on this planet, there is no individuality. It may sound ridiculous to say so, but I believe each person is but a wave passing through space, ever-changing from minute to minute as it travels along, finally, some day, just becoming dissolved.

The only method compatible with our notions of civilization and the race is to prevent the breeding of the unfit by sterilization and the deliberate guidance of the mating instinct. [...] The trend of opinion among eugenists is that we must make marriage more difficult. Certainly no one who is not a desirable parent should be permitted to produce progeny.

The scientists of today think deeply instead of clearly. One must be sane to think clearly, but one can think deeply and be quite insane.

I would not give my rotating field discovery for a thousand inventions, however valuable... A thousand years hence, the telephone and the motion picture camera may be obsolete, but the principle of the rotating magnetic field will remain a vital, living thing for all time to come.

My ear barely caught signals coming in regular succession which could not have been produced on earth.

To create and to annihilate material substance, cause it to aggregate in forms according to his desire, would be the supreme manifestation of the power of Man's mind, his most complete triumph over the physical world.