The color of the object illuminated partakes of the color of that which illuminates it.

The sun gives spirit and life to the plants and the earth nourishes them with moisture.

Make your faces so that they do not all have the same expression, as one sees with most painters, but give them different expression, according to age, complexion, and good or bad character.

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

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

Every part is disposed to unite with the whole, that it may thereby escape from its own incompleteness.

No human investigation can be called real science if it cannot be demonstrated mathematically.