Petrić’s criticism of Aristotle is rooted in a specific understanding and interpretation of Aristotle’s philosophy, as well as in a specific understanding of Plato’s philosophy. In Discussionum peripateticarum T. IV, in the chapter on the difference of opinions between Aristotle and Plato in matters concerning dialectics, at issue is a rather specific understanding of what dialectics actually is. Although Petrić equates dialectics with logic, the topic and discipline of formal logic, in the sense of it being the organon of philosophy, is not what is at issue here; rather, what Petrić concerns himself with is a tight connection between metaphysical, gnoseological and logical matters. Petrić founds the differences between Aristotle and Plato in Aristotle’s two most fundamental ontological standpoints (naturally, in the way that he perceives and interprets them): the creation of the human soul from matter and the concept of a being as an originated, created being that is encompassed by the ten categories. These are the standpoints from which Petrić disputes the cognitive meaning of Aristotle’s syllogism and proof, as well as his criticism of definitions and diaeresises. The chapter culminates in Petrić’s interpretation of Plato’s comparison with the line that Petrić expounds as being contrary to the renaissance understanding of Aristotle’s proofs of ὅτι and διότι. It is obvious that at issue here is Petrić’s criticism of a theory that was then well-known and that was inspired by Aristotle’s philosophy, rather than a criticism of Aristotle.