Leonardo da Vinci on nature

Iron rusts from disuse; stagnant water loses its purity and in cold weather becomes frozen; even so does inaction sap the vigor of the mind.

Simplicity is the ultimate sophistication.

Anyone who invokes authors in discussion is not using his intelligence but his memory.

Every day, man is making bigger and better fool-proof things, and every day, nature is making bigger and better fools. So far, I think nature is winning.

Albert Einstein1879–1955

Nature does nothing uselessly.

Aristotle384–322 BCPolitics, Book I, 1253a.8

Nature scarcely ever gives us the very best; for that we must have recourse to art.

Baltasar Gracián1601–1658

• Art