Why did Leonardo da Vinci argue that painting was a science?

Leonardo da Vinci argued that painting was a science to elevate its status from a mechanical craft to one of the liberal arts. His defense was rooted in the belief that the painter, through superior powers of perception and the ability to reproduce the world, was uniquely qualified to achieve true knowledge.1

Key reasons for his argument include:

• The Primacy of Sight: Leonardo asserted that the eye is the most reliable sense, as it provides immediate, correct, and certain facts of experience. He believed that the direct observation required for painting possessed a truthful, scientific quality.12
• Mathematical and Optical Foundations: He maintained that painting relies on rigorous principles, including geometry, proportion, and the 10 optical functions of the eye. His work incorporated complex systems of perspective, such as linear and aerial perspective, to accurately depict the physical world.1
• Comparison to Other Arts: Through the paragone (comparison), he argued that painting is superior to poetry because it presents results that provide immediate satisfaction, mirroring the way nature itself is perceived.1