 In Parts two and three, he is to some extent successful in applying geometry to problems of direct, reflected, and refracted vision. He moved the study of these matters to a new level. The geometrical arguments are worked out with careful diagrams and various appeals are made to “experimental” conditions. What are these conditions? Some of them are simple thought-experiments or even reports of actual experiments from earlier writers. It seems clear, however, that Bacon himself did experimental work with pinhole images, lenses, and discrete observations. This does not lead to a pure geometrization of nature, however, and he inevitably falls back on physical, perceptual, and metaphysical arguments. One might argue that he lacks the notion of infinity that is present in modern geometry.