Relativity applies to physics, not ethics.

A mathematical equation stands forever.

[Freud's] sense of reality is less clouded by wishful thinking than is the case with other people and [he combines] the qualities of critical judgment, earnestness and responsibility.

There are times when one feels liberated from one’s limits and human imperfections. At such moments, we see ourselves there, in a little corner of our little planet, our eyes fixed in wonder on the cold and yet deep beauty of that which is eternal, that which is elusive. Life and death are fused together and there is no evolution, nor destination, there is only BEING.

I cannot conceive of a personal God who would directly influence the actions of individuals, or would directly sit in judgment on creatures of his own creation.

You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat.

I am convinced there is only one way to eliminate these grave evils, namely through the establishment of a socialist economy, accompanied by an educational system which would be oriented toward social goals.