The noblest pleasure is the joy of understanding.

Anyone who in discussion relies upon authority uses, not his understanding, but rather his memory.

As a well-spent day brings happy sleep, so a life well used brings happy death.

Simplicity is the ultimate sophistication.

There are three classes of people: those who see, those who see when they are shown, those who do not see.

Where the spirit does not work with the hand, there is no art.