Men do wrong to lament the flight of time, complaining that it passes too quickly and failing to perceive that its period is sufficiently long; but a… - Leonardo da Vinci

Men are in error when they lament the flight of time, accusing it of being too swift, and not perceiving that it is sufficient as it passes; but good memory, with which nature has endowed us, causes things long past to seem present.

The earth is not in the centre of the Sun's orbit nor at the centre of the universe, but in the centre of its companion elements, and united with them. And any one standing on the moon, when it and the sun are both beneath us, would see this our earth and the element of water upon it just as we see the moon, and the earth would light it as it lights us.

Painting is concerned with all the 10 attributes of sight; which are: Darkness and Light, Solidity and Color, Form and Position, Distance and Propinquity, Motion and Rest.

The worst evil which can befall the artist is that his work should appear good in his own eyes.