“The development of science and of the creative activities of the spirit requires a freedom that consists in the independence of thought from the restrictions of authoritarian and social prejudice.”

“To raise new questions, new possibilities, to regard old problems from a new angle, requires creative imagination and marks real advance in science.”

“In scientific thinking are always present elements of poetry. Science and music requires a thought homogeneous.”

“I fully agree with you about the significance and educational value of methodology as well as history and philosophy of science. So many people today - and even professional scientists - seem to me like somebody 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.[Correspondance to Robert Thorton in 1944]”

“Few people are capable of expressing with equanimity opinions which differ from the prejudices of their social enviroment. Most people are incapable of forming such opinions."(Essay to Leo Baeck, 1953)”

“All religions, arts and sciences are branches of the same tree. All these aspirations are directed toward ennobling man's life, lifting it from the sphere of mere physical existence and leading the individual towards freedom.”

“We experience ourselves our thoughts and feelings as something separate from the rest. A kind of optical delusion of consciousness. This delusion is a kind of prison for us, restricting us to our personal desires and to affection for a few persons nearest to us.”