Sébastien Le Clerc (1637–1714) led a remarkably diverse career, engraver, cartographer, theorist of fortification, and writer on optics, architecture, and cosmology, while championing engraving as an art equal to painting and turning his workshop into a hub of learned sociability. By examining the interplay of these varied practices, Antoine Gallay explores the complex relations between arts and knowledge at the dawn of the Enlightenment, illuminating the origins of our modern dichotomy between art and science.