Where the world ceases to be the scene of our personal hopes and wishes, where we face it as free beings admiring, asking and observing, there we enter the realm of Art and Science.

There are few enough people with sufficient independence to see the weaknesses and follies of their contemporaries and remain themselves untouched by them.

You cannot simultaneously prevent and prepare for war.

No one must think that Newton’s great creation can be overthrown in any real sense by this [Theory of Relativity] or by any other theory. His clear and wide ideas will for ever retain their significance as the foundation on which our modern conceptions of physics have been built.

Overemphasis of the competitive system and premature specialization on the ground of immediate usefulness kill the spirit on which all cultural life depends, specialized knowledge included.

You can never solve a problem on the level on which it was created.

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.