Leonardo da Vinci thought sight was humankind’s most important sense and eyes the most important organ, and he stressed the importance of saper vedere, or “knowing how to see.” He believed in the accumulation of direct knowledge and facts through observation.“A good painter has two chief objects to paint — man and the intention of his soul,” da Vinci wrote. “The former is easy, the latter hard, for it must be expressed by gestures and the movement of the limbs.” @lndesta120282