 Bacon ends Part three with an account of how a better understanding of natural phenomena could lead to a more accurate knowledge of the natural phenomena mentioned in Scripture. He finds in visual phenomena significant metaphors and analogies for use in moral and religious teaching. A solution to David C. Lindberg’s queries about Bacon’s attempt to combine elements of the intromissionist and extramissionist theories of vision is addressed here. At one level, it seems to be an akward combination of two conflicting theories of vision. This combination can be understood when one notes that Bacon is making use of the important issue of grace and free will issue as the moral-religious background for his discussion of vision. In other words, genuine theological concerns influence the manner in which Bacon constructs his analysis of vision in the Perspectiva. Thus, the analyses of Ptolemy and Alhacen had to be synthesized within a definite theological framework.