Nature is full of infinite reasons which have not yet passed into experience.

The vivacity and brightness of colors in a landscape will never bear any comparison with a landscape in nature when it is illumined by the sun, unless the painting is placed in such a position that it will receive the same light from the sun as does the landscape.

A single and distinct luminous body causes stronger relief in the objects than a diffused light; as may be seen by comparing one side of a landscape illuminated by the sun, and one overshadowed by clouds, and illuminated only by the diffused light of the atmosphere.

To any white body receiving the light from the sun, or the air, the shadows will be of a bluish cast.

Look at light and admire its beauty. Close your eyes, and then look again: what you saw is no longer there; and what you will see later is not yet.

He who is not content to look, like a savage, at the phenomena of nature as disconnected, cannot any longer believe that man is the work of a separate act of creation ... Man is the co-descendant with other mammals of a common progenitor.