Most mistakes in philosophy and logic occur because the human mind is apt to take the symbol for the reality.

The devil has put a penalty on all things we enjoy in life. Either we suffer in our health, or we suffer in our soul, or we get fat.

The relativity principle in connection with the basic Maxwellian equations demands that the mass should be a direct measure of the energy contained in a body; light transfers mass. With radium there should be a noticeable diminution of mass. The idea is amusing and enticing; but whether the Almighty is laughing at it and is leading me up the garden path -- that I cannot know.

When a man, after long years of searching, chances upon a thought which discloses something of the beauty of this mysterious universe, he should not therefore be personally celebrated. He is already sufficiently paid by his experience of seeking and finding.

I prefer an attitude of humility corresponding to the weakness of our intellectual understanding of nature and of our own being.

Example isn't another way to teach, it is the only way to teach.

The problems that exist in this world can not be solved by the level of thinking that created them.