There will be many which will increase in their destruction. — Leonardo da Vinci

"Painting is poetry which is seen and not heard, and poetry is a painting which is heard but not seen. These two arts, you may call them both either poetry or painting, have here interchanged the senses by which they penetrate to the intellect."

"Though I may not, like them, be able to quote other authors, I shall rely on that which is much greater and more worthy — on experience, the mistress of their Masters. They go about puffed up and pompous, dressed and decorated with [the fruits], not of their own labours, but of those of others. And they will not allow me my own. They will scorn me as an inventor; but how much more might they — who are not inventors but vaunters and declaimers of the works of others — be blamed."

"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."

"Seeing that I can find no subject specially useful or pleasing — since the men who have come before me have taken for their own every useful or necessary theme — I must do like one who, being poor, comes last to the fair, and can find no other way of providing himself than by taking all the things already seen by other buyers, and not taken but refused by reason of their lesser value. I, then, will load my humble pack with this despised and rejected merchandise, the refuse of so many buyers; and will go about to distribute it, not indeed in great cities, but in the poorer towns, taking such a price as the wares I offer may be worth."

"King of the animals — as thou hast described him — I should rather say king of the beasts, thou being the greatest — because thou hast spared slaying them, in order that they may give thee their children for the benefit of the gullet, of which thou hast attempted to make a sepulchre for all animals; and I would say still more, if it were allowed me to speak the entire truth . But we do not go outside human matters in telling of one supreme wickedness, which does not happen among the animals of the earth, inasmuch as among them are found none who eat their own kind, unless through want of sense."

"Oysters 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."