Abstract

The paper presents evidence that Roger Bacon was endeavoring to structure what he considered as a “new metaphysics”. Moreover, it identifies the Opus maius as Bacon’s new preliminary text in metaphysics and morals. The evidence is found in the Communia naturalium and in the Communia mathematica, in which one finds a reference to the Opus maius as a sketch for a new metaphysics. From part seven of the latter work, namely, the Moralis philosophia, one can see that Bacon views the latter work as closely connected to his new metaphysics. In fact, the material in the Communia mathematica connects his studies on languages to the communication of his moral vision. I present a review of the sources for the different parts of the Opus maius. This is followed by an account of Bacon’s philosophical sources. It becomes clear that Bacon was acquainted with Plato’s Meno, Phaedo and part of the Timaeus with Calcidius’s Commentary. The variety and significance of his Neo-Platonic sources are outlined. It turns out that Bacon was not an Avicennian substance-dualist. Moreover, the paper demonstrates the extent to which Bacon’s criticism of Averroes was based on his natural philosophy. Bacon presents an account of human intellectual knowledge which is clearly based on and refers to his account of human perceptual knowledge in his Perspectiva. He uses his account of an integrated perceptual and intellectual human individual being to question the Latin Averroist’s claim that there is one possible intellect for all human beings.