Leonardo was first and foremost a polymath inventor and creator. Whether looking at plants, musical harmonies, or elliptical curves of cannon balls, he was fascinated by the world around him. His indiscriminate exploration of the diversity of human and natural knowledge—arts, humanities, sciences and technology—turned him into the exemplar of what is now called a Renaissance man. Leonardo left behind over 6,000 drawings that reveal his scientific, theoretical, and creative mental worlds that remained largely unknown before the 19th century. Since then, however, his writings, overflowing with artistic, scientific, and technological inventions, have become almost more famous than his artwork. They reveal a polymath whose prescient observations and scientific analyses seem to foreshadow later discoveries.