It is humankind's duty to respect all life, not only animals have feelings but even also trees and plants.

We must remember that we do not observe nature as it actually exists, but nature exposed to our methods of perception. The theories determine what we can or cannot observe...Reality is an illusion, albeit a persistent one.

Everything has changed except the way man thinks (when the hydrogen bomb was exploded)

I sometimes ask myself how it came about that I was the one to develop the theory of relativity. The reason, I think, is that a normal adult never stops to think about problems of space and time. These are things which he has thought about as a child. Bu t my intellectual development was retarded,as a result of which I began to wonder about space and time only when I had already grown up.

In the past it never occurred to me that every casual remark of mine would be snatched up and recorded. Otherwise I would have crept further into my shell.

Most teachers waste their time by asking question which are intended to discover what a pupil does not know whereas the true art of questioning has for its purpose to discover what pupils knows or is capable of knowing.

Thought is the organizing factor in man, intersected between the causal primary instincts and the resulting actions.