The archetypal Renaissance man, Leonardo da Vinci is admired for his unequaled range of intellectual passions. The creator of the Mona Lisa and other artistic masterpieces in the second half of the 1400s and early 1500s was also an accomplished musician, scientist and engineer whose inventions included ball bearings, instruments to measure the specific gravity of solids, and fantastic war machines (although he abhorred the “most bestial insanity” of battle).
Less well known—largely because hundreds of pages of his notes and detailed anatomical drawings went unpublished until the late 19th and early 20th centuries—are his remarkable and penetrating findings in the field of neuroscience. In an era more comfortable accepting notions handed down from medieval science and ancient Greece and Rome, he pioneered the practice of sketching anatomical features based on his own direct observations. He also strove to establish a physical basis by which the brain interprets sensory stimuli and through which the mind functions. And he developed a coherent theory of how the senses operate, in particular how the eye sees—mechanistic explanations of such phenomena that reflect the thinking typical of his primary career, engineering.