Published online by Cambridge University Press: 26 May 2022
Averroes's Commentary on Plato's “Republic” goes far beyond merely commenting on the original. With the benefit of 1,500 years of hindsight, it reckons with important works of philosophy that would have been completely unknown to Plato. Averroes mentions three authors of such works by name: Galen, whom he mostly rebukes, Aristotle, and Alfarabi. It would be hasty to assert that by including such extraneous material, Averroes departs from Plato, but, at the very least, he updates him on account of historical developments.
The importance of Averroes's post-Platonic additions is evident from the very structure of the work. The part of it that can plausibly claim to be a commentary on Plato does not begin until 27.24, almost seven pages into Rosenthal's Hebrew text. Averroes begins to address the subject of war, corresponding to Republic 374b, having skipped all of book 1 and the majority of book 2, with only two brief references to them in the opening section (CR 22.27–30, 23.31–33, cf. 47.29–30and 105.25–27). Averroes does not justify his omission until the very end of the work, when he states that the opening part of the Republic does not contain any of the demonstrative arguments of which his commentary is comprised (CR 105.25–27, cf. 21.4). He is more immediately forthright about the reasons for what he includes in its place. In keeping with the demonstrative focus of the work, Averroes replaces Platonic dialectic with a substantial discussion of science. Having divided practical science into two parts, one about general habits and actions and another about their implementation, Averroes explains: “Before we begin a point-by-point explanation of what is in these arguments [of Plato], we ought to mention the things pertinent to this [second] part [of practical science] and explained in the first part, that serve as foundation for what we wish to say here at the beginning” (CR 22.6–8). Averroes's introduction concerns above all the first part of political science, while the Republic proper contains only the second. Averroes attributes to Plato only a small part of the ensuing discussion, concerning justice, the division of labor, and the arrangement of the soul (CR 22.22–24.6, esp. 22.27, 23.31). The other passages are inspired by Aristotle and especially Alfarabi. Averroes appears to substitute scientific arguments from Aristotle and Alfarabi—mainly about science, philosophy, courage, and war—for Plato's dialectical introduction about justice and the founding of the just city.