There are many kinds of beauty as people who possess it.

We know more about the movement of celestial bodies than about the soil underfoot.

O neglectful Nature, wherefore art thou thus partial, becoming to some of thy children a tender and benignant mother, to others a most cruel and ruthless stepmother? I see thy children given into slavery to others without ever receiving any benefit, and in lieu of any reward for the services they have done for them they are repaid by the severest punishments.

I have offended God and mankind because my work didn't reach the quality it should have.

The painter who has no doubt about his own ability will attain very little.

It's not enough that you believe what you see. You must also understand what you see.

No human investigation can claim to be scientific if it doesn't pass the test of mathematical proof.