The world we have made is a result of the level of thinking we have done thus far.

I believe that the horrifying deterioration in the ethical conduct of people today stems from the mechanization and dehumanization of our lives. A disastrous by-product of the development of the scientific and technical mentality. We are guilty. Man grows cold faster than the planet he inhabits.

Opinions about obviousness are to a certain extent a function of time.

It would seem that men always need some idiotic fiction in the name of which they can hate one another. Once it was religion. Now it is the State.

[Kepler] had to realize clearly that logical-mathematical theoretizing, no matter how lucid, could not guarantee truth by itself; that the most beautiful logical theory means nothing in natural science without comparison with the exactest experience. Without this philosophic attitude, his work would not have been possible.

So I am living without fats, without meat, without fish, but am feeling quite well this way. It always seems to me that man was not born to be a carnivore.

This is a question too difficult for a mathematician. It should be asked of a philosopher"(when asked about completing his income tax form)