He was most famous as an artist (and his Mona Lisa and The Last Supper are two of the best-known paintings of the Renaissance). His scientific work was mostly unpublished, little known in his lifetime, and so had little effect on the course of natural philosophy. But his later fame as an artist also overshadowed his work as an engineer. As was typical of his day, much of this was contracted work, not meant to be scholarly or published, but produced, like the art, for patrons.

After 1481, Leonardo worked as an artist and adviser to the court of Ludovico Sforza of Milan. There his work shows the interaction of mathematics with his designs and art. He wrote in notes on painting, for an intended text, compiled and published later as Trattato della Pittura [Treatise on Painting * ],

“No human investigation can be called a science if it does not capable of mathematical demonstration. If you say that the sciences which begin and end in the mind are true, this is not conceded, but denied for many reasons, and foremost among these is the fact that the test of experience is absent from these exercises of the mind, and without these there is no assurance of certainty.”

Here we see the move toward empirical knowledge, modeled and expressed with the aid of mathematics.