The Capuchin monk Valeriano Magni tried to create a new Christian, anti-Aristotelian philosophy, which also includes an alternative concept of sense perception. The main source of his approach is St. Augustine’s and St. Bonaventure’s theory of illumination and the metaphysics of light. Magni emphasizes the seeing is the only sense by means of which one can attain cognition of bodies, i.e., their extension and colour. At the same time, through an analysis of the inner processes of sensation, cognition and intellection, seeing leads to self-awareness. Cognition is intentional in character. The object of sense perception is not an actual external object but an image of it originating from the object, received by the sense organ and grasped by the soul vitalizing the sense organ. Despite that Magni regards the sense data provided by seeing as per se nota, which is made possible by the metaphysics of light. For Magni, light is an epistemological, ontological, and physical principle. His emphasis on seeing is a part of his ontological programme.