All these constructions and the laws connecting them can be arrived at by the principle of looking for the mathematically simplest concepts and the link between them.

Conventional words or other signs have to be sought for laboriously only in a second stage, where the associative play already referred to is sufficiently established and can be reproduced at will.

A conviction akin to religious feeling of the rationality or intelligibility of the world lies behind all scientific work of a high order.

I am satisfied with the mystery of life's eternity and with a knowledge, a sense, of the marvelous structure of existence - as well as the humble attempt to understand even a tiny portion of the Reason that manifests itself in nature.

You are right in speaking of the moral foundations of science, but you cannot turn around and speak of the scientific foundations of morality.

The high destiny of the individual is to serve rather than to rule.

I am content in my later years. I have kept my good humor and take neither myself nor the next person seriously.