Learning never exhausts the mind.

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

It vexes me greatly that having to earn my living has forced me to interrupt the work and to attend to small matters.

The fox when it sees a flock of herons or magpies or birds of that kind, suddenly flings himself on the ground with his mouth open to look as he were dead; and these birds want to peck at his tongue, and he bites off their heads.

Everything proceeds from everything else and everything becomes everything, and everything can be turned into everything else.

Why are the bones of great fishes, and oysters and corals and various other shells and sea-snails, found on the high tops of mountains that border the sea, in the same way in which they are found in the depths of the sea?

Just as iron rusts from disuse, and stagnant water putrefies, or when cold turns to ice, so our intellect wastes unless it is kept in use.