Nature made us - nature did it all - not the gods of the religions.

Human subtlety will never devise an invention more beautiful, more simple or more direct than does nature because in her inventions nothing is lacking, and nothing is superfluous.

The wisest and noblest teacher is nature itself.

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

The air moves like a river and carries the clouds with it; just as running water carries all the things that float upon it.

The painter will produce pictures of little merit if he takes the works of others as his standard: but if he will apply himself to learn from the objects of nature he will produce good results. This we see was the case with the painters who came after the time of the Romans, for they continually imitated each other, and from age to age their art steadily declined.