Any man may be in good spirits and good temper when he is well dressed. There ain't much credit in that.

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. 

In order to carry a positive action we must develop here a positive vision.

You have enemies? Good. That means you've stood up for something, sometime in your life. 

Everything should be made as simple as possible, but not simpler.

Whatever I have tried to do in life, I have tried with all my heart to do it well; whatever I have devoted myself to, I have devoted myself completely; in great aims and in small I have always thoroughly been in earnest.

All paid jobs absorb and degrade the mind.

Our judgments when we are pleased and friendly are not the same as when we are pained and hostile.

Never neglect details. When everyone's mind is dull or distracted the leader must be doubly vigilant.

Measures must always in a progressive society be held superior to men, who are after all imperfect instruments, working for their fulfilment.

Health is the greatest gift, contentment the greatest wealth, faithfulness the best relationship.

It is a far, far better thing that I do, than I have ever done; it is a far, far better rest that I go to, than I have ever known.