Marriage is neither heaven nor hell, it is simply purgatory.

I claim to be a simple individual liable to err like any other fellow mortal. I own, however, that I have humility enough in me to confess my errors and to retrace my steps.

It is only so long as a man can retain the child in him that life can be free from those dark shadows which leave inevitable furrows on a man’s forehead.

After climbing a great hill, one only finds that there are many more hills to climb.

Truth is by nature self-evident. As soon as you remove the cobwebs of ignorance that surround it, it shines clear.

If I were not a physicist, I would probably be a musician. I often think in music. I live my daydreams in music. I see my life in terms of music. 

Never lose a holy curiosity.

The one exclusive sign of thorough knowledge is the power of teaching.

Each one has to find his peace from within. And peace to be real must be unaffected by outside circumstances.

What you are will show in what you do.

Sometimes, I feel like one who is on the sidelines, who has missed life itself.

When you have got an elephant by the hind legs and he is trying to run away, it's best to let him run.