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.

I am even grateful to Einstein and others because through their erroneous theories they lead mankind away from that dangerous path I followed.

If you only knew the magnificence of the 3, 6 and 9, then you would have the key to the universe.

A single ray of light from a distant star falling upon the eye of a tyrant in bygone times may have altered the course of his life, may have changed the destiny of nations, may have transformed the surface of the globe, so intricate, so inconceivably complex are the processes in Nature.

But I hope that it will also be demonstrated soon that in my experiments in the West I was not merely beholding a vision, but had caught sight of a great and profound truth.

Nature may reach the same result in many ways.

The present is theirs; the future, for which I really worked, is mine.