I believe in mystery and, frankly, I sometimes face this mystery with great fear. In other words, I think that there are many things in the universe that we cannot perceive or penetrate, and that also we experience some of the most beautiful things in life only in a very primitive form. Only in relation to these mysteries do I consider myself to be a religious man.

Although I have been prevented by outward circumstances from observing a strictly vegetarian diet, I have long been an adherent to the cause in principle. Besides agreeing with the aims of vegetarianism for aesthetic and moral reasons, it is my view that a vegetarian manner of living by its purely physical effect on the human temperament would most beneficially influence the lot of mankind.

Pure mathematics is, in its way, the poetry of logical ideas. ... [By seeking] logical beauty spiritual formulas are discovered necessary for the deeper penetration into the laws of nature.

I fully agree with you about the significance and educational value of as well as history and philosophy of science. So many people today - and even professional - seem to me like someone who has seen thousands of trees but has never seen a forest. A knowledge of the historic and philosophical background gives that kind of independence from prejudices of his generation from which most scientists are suffering. This independence created by philosophical insight is - in my opinion - the mark of distinction between a mere artisan or specialist and a real seeker after truth.

Scientists investigate that which already is; Engineers create that which has never been.

I am also convinced that one gains the purest joy from spirited things only when they are not tied in with earning one's livelihood.

The value of a man resides in what he gives