Leonardo da Vinci receives excessive praise for his work as a painter. The Louvre, home to some of the world’s finest classical paintings, dedicates an entire room to the diminutive Mona Lisa, and millions flock to it every year. Although da Vinci possessed natural artistic ability and an artistic eye, he revealed his preeminent talent as a student of science, not a portrait painter, through his journals on anatomy and nature.

Leonardo combined art and science by sketching his inventions and observations. He refused to accept secondhand accounts of nature and took an experiential approach, including working with cadavers, to observe muscle and bone structure. Da Vinci did not conduct these studies for medical or philosophical purposes. He had no interest in why birds take to the air or the connection between flight and soul; he simply wanted to discover how countless parts collaborate to form a working system.

Centuries ago, Leonardo sketched an embryo with accuracy commensurate with modern medical textbooks. One of thousands by da Vinci, this illustration showcases the delicacy and detail for which Leonardo gained fame. He transferred his knowledge of the human form to his paintings, but this sketch, found in one of his numerous journals, was created to aid understanding, not to be a masterpiece. Regardless of intention, so-called Embryo in Womb captures Leonardo’s facility and overlooked range of work.