So is cheerfulness, or a good temper, the more it is spent, the more remains.

Accuracy is a duty, not a virtue.

I am not a teacher, but an awakener.

Do not pity the dead, Harry, pity the living, and above all those who live without love.

Never give up. Great things take time.

Sometimes when you innovate, you make mistakes. It is best to admit them quickly and get on with improving your other innovations.

The best cure for the body is a quiet mind.