 In the second chapter, Bacon attacks some of the leading philosophers at Paris: “But the leaders of the common philosophers at Paris fall into other deadly errors, which the theologians contradict” ([OHI, IV], 284). For about ten years, the leader of the philosophers, “an erroneous and famous man,” held that “prior to the existence of the rational soul, one must presuppose a specific substantial difference educed from the potency of matter which places man in the species of animal, such that the intellective soul does not do so…This is contrary to the philosophy of Aristotle and to all authors” ([OHI, IV], 284–85). A study of the Questiones on De anima indicates the earlier Parisian tradition out of which Bacon is working (Bernardini 2009; see also Bernardini 2014). In the third chapter, Bacon makes explicit the object of his polemic. It is the view commonly ascribed to Siger of Brabant and the so-called Radical Aristotelians (Latin Averroists). Bacon states: