O time, swift robber of all created things, how many kings, how many nations hast thou undone, and how many changes of states and of various events have happened since the wondrous forms of this fish perished here in this cavernous and winding recess. Now destroyed by time thou liest patiently in this confined space with bones stripped and bare; serving as a support and prop for the superimposed mountain.
Leonardo da VinciIf a man has a tent made of linen of which the apertures have all been stopped up, and be it twelve bracchia across (over twenty-five feet) and twelve in depth, he will be able to throw himself down from any height without sustaining injury. [His concept of the parachute.]
Leonardo da VinciJust 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.
Leonardo da VinciOysters open completely when the moon is full; and when the crab sees one it throws a piece of stone or seaweed into it and the oyster cannot close again so that it serves the crab for meat. Such is the fate of him who opens his mouth too much and thereby puts himself at the mercy of the listener.
Leonardo da VinciAnd you who wish to represent by words the form of man and all the aspects of his membrification, relinquish that idea. For the more minutely you describe the more you will confine the mind of the reader, and the more you will keep him from the knowledge of the thing described. And so it is necessary to draw and to describe.
Leonardo da Vinci