Literary and Philosophical Fragments

of the Mona Lisa original: Gioconda is an achievement no less powerful than the discovery of those laws of perspective and optics which help us to see it. When Leonardo, to "many ingenious citizens who then governed Florence," showed his desire to raise the Baptistery of San Giovanni or to straighten the course of the Arno, "he persuaded them with such strong reasons that it seemed possible, although everyone, once he had left, recognized for themselves the impossibility of such a great undertaking.*" But which of these "ingenious citizens," while condemning the practical intention, ever thought to ask Da Vinci what the mechanical principles The physical laws governing the motion and force of machines. or hydraulic principles The study of the movement and pressure of liquids, particularly water. were that led him to believe it feasible? If he did not lift San Giovanni, nor channel the Arno, this does not matter: his true work lies in the Treatise on Local Motion, Percussions, Weights, and All Forces, where he foreshadows, and in some points surpasses, the Dialogues Concerning Two New Sciences of... Referring to Galileo Galilei’s foundational work on physics, published over a century after Leonardo's death.

• The Lives original: Le Vite by Giorgio Vasari, the foundational biographer of Renaissance artists., vol. IV, pages 50-51, 21.