Abstract
My goal in this paper is to contribute to the literature on Roger Bacon's epistemology by focusing on the issue of perception of quantity. The reading I aim to substantiate is that Bacon's account is best understood in terms of indirect realism. I call it indirect realism because although we have access to quantities as they exist in nature, the account is mediated by the use of a quasi-syllogism. The quasi-syllogism is constructed based on three inputs, the species of the eye, colour, and light. To defend this reading I follow five steps. First, I analyse the importance of quantity in perception, and then, in steps two and three, I look at Bacon's theory of perception from its two sides, extramission and intromission. In the fourth step I look at the quasi-syllogisms that mediate cognition of quantities, and in the fifth and final step, I draw all the threads together and make the case for Bacon's indirect realism of quantity perception.