But anyone who has been that young knows that the great grief of love is that your body feels the most when it knows the least.

The Devil may take the reckless, but the good will surely die of boredom. Boredom and frustration.

If grace belongs to God, there are those who say that luck belongs to the Devil and that he looks after his own.

Ah, he has too many ideas, that man da Vinci. His mind works faster than his hands.

Missing rubs the soul raw.

So if we could not have love, my husband and I, then at least I could have alchemy.

Family. The greatest loyalty after God.

There's a fine line between genius and insanity. I have erased this line.

You can’t make a difference if you are not trained in the principles of God

. . . she tried to weave the strength of her father and the young beauty of her first love with David, the happy oblivion of her teens and her warm protected childhood into a magic cloak.

...once students have been taught that learning is tedious, difficult, and useless, they will never learn another lesson.

An ill principle in the mind is worse than the matter of a disease in the body.

Liberty (individual freedom) is the prize, responsibility the price.

Moral contempt is a far greater indignity and insult than any kind of crime.

Success is terrifying. Like happiness, it is often appreciated in retrospect. It's only later that you place it in perspective. Years from now, I'll look back and say, ‘God, wasn't it wonderful.’

The law of love knows no bounds of space or time.

It is my earnest desire that some of you should carry on this scientific work and keep for your ambition the determination to make a permanent contribution to science.