Joshua Weinstein's new book makes a substantial contribution to our understanding of the Republic by paying close attention to early stages of the argument for the city-soul analogy in books II–IV. Weinstein argues persuasively that these books are fundamentally political (correcting the tendency see the real political theory of the Republic as starting in book V), and that the elements of tripartite psychology are systematically developed from the founding of the city (rather than depending solely on arguments in book IV). His reconstruction of the argument is judicious and careful, and focuses on the text of the Republic.

The work is fittingly divided into three parts. Weinstein's strategy is to identify and motivate the arguments for the tripartite division of soul and city, thus illuminating the nature of justice and its inner workings (7). He details three arguments that establish Plato's position: an argument from a diversity of characters and lives, an argument from an opposition of motivations, and an argument from the sufficiency of function of each of the soul parts (7). Part 1 argues that Plato relies on a “recognized sociology” (11) or “observational anthropology” (43), establishing three basic kinds of character: wisdom loving, victory loving, and profit loving. While there are different manifestations or orderings of these drives to curiosity, ambition, and acquisition in different people, ultimately there are only three basic drives or motivations (59). Thus, there are three (and only three) soul parts because there are three distinctive drives and lives, even though there are multifarious psychological effects from their interactions.

Part 2 moves to the development of the just city. Weinstein's methodology is to explain the function of the parts by considering self-sufficiency: “if the lack of a certain part precludes the self-sufficiency of the political whole, then that part can be said to have a function in the whole, and it can thus be said to ‘do its own’ (or not) as it contributes justly to the good life of the whole” (106). Using the city analogy advances Plato's argument because the functions required for a self-sufficient city are easier to identify, yet they also correspond directly to the functions of the soul. Weinstein then departs from scholarly orthodoxy in explaining the “one person one job” principle not by reference to the pragmatic efficiency of division of labor (which he insightfully critiques) but by reference to the analytical argument from function: the jobs of the city need to be clearly identifiable in the formal structure of the city for us to understand each function (118).

Weinstein then explains the development of the city: first, basic bodily needs must be accounted for, but the need to trade, sell, and distribute goods leads the city to include merchants and move “from socialism to capitalism” (124). Though it satisfies basic needs, the early city has no awareness that this is its purpose and thus no internal limit on what it produces (132). In order to appease the senses and generate pleasure, the city begins to produce luxuries, but the unrestrained pursuit of luxuries leads to war (147): increasing demand for luxuries increases population growth and puts pressure on limited land, but without a correlate increase of food supplies the city eventually begins to starve (152–57). The solution is to invade neighboring territories for farmland––and this requires an army. The argument from function then requires a class of specialist soldiers. But without guidance of whom to fight and when to fight, the soldiers cannot perform their function well. Thus the need for the soldiers to be led prompts the inclusion of philosophers (161). In each case, the higher classes of the city correct the deficiencies of the lower and collectively form a self-sufficient whole.

Part 3 returns to concerns about the function of the spirited part of the soul and about its necessity. Weinstein's key claim is that “no amount of reason is sufficient, on its own, to make up for the failings of the appetites” (204). Because the appetites’ drive to luxury and excess cannot be “argued away” and the appetites are prone to usurp reason through rationalization, there must be a soul part whose job it is to use force to hold oneself to one's reasoned commitments. Weinstein thus argues that spirit's love of victory is manifest in a desire to succeed in achieving one's ends (242). While some commentators understand the spirited part of the soul as seeking positional or social goods, Weinstein focuses on the description of spirit as the preserver. Because the success of our projects involves overcoming pleasure or pain, spirit has a necessary function to play in successful agency by preserving our goals and plans. This framework allows Weinstein to segue into a discussion of the time valence of spirit, which focuses on mid-term goals in the face of short-term temptations. The account of characteristic temporalities of each soul part is the most speculative part of the book, but the view deserves careful reflection and its mechanics become clearer as the book progresses (esp. 261).

On the whole, Weinstein's arguments are compelling and rely on reasonable interpretations of the text. There are, however, moments where the framing of particular issues is puzzling. Readers may be surprised when Weinstein attributes different characters and ways of life to soul parts (92). Commentators normally understand character as what emerges from one's soul taken as a whole, even though one's particular beliefs, desires, and impulses might conflict. Weinstein thus departs from a common view about each soul part having characteristic powers and desires, and those desires shaping one's life if they dominate in the soul. Rather, he claims that “Plato sees every individual as living, at certain times and under some circumstances, each of the three lives” (55). Weinstein attempts to clarify this paradox by describing character as a “fractal in time” (56)––but layered metaphors become murky here, and one might worry that Weinstein has used the explanandum (different characters) to motivate the proposed explanans (different soul parts).

More constructively, Weinstein might profitably develop his views by engaging with the literature on imperfect or nonphilosophical virtue to explore ways in which appetitive and thumotic forces can be controlled without the perfection of one's own reason. Though the “highest expression” of reason is found in one's own knowledge of the Forms (198), Weinstein's account leaves open the possibility that other kinds of guidance from reason might result in political good functioning (for example, through law or the direction of wise rulers). While Weinstein has shown how appetite and spirit cannot be left to their own devices without nefarious consequences, Plato suggests that there are a number of ways in which to create order in the city and the soul without everybody becoming a philosopher.

In sum, Weinstein's book is primarily about the moral psychology of the Republic—and it is an excellent and insightful book for scholars interested in this aspect of Plato's thought. Moreover, it is essential reading for scholars working on any aspect of Republic II–IV. Some readers of this journal may find the long discussions of psychology slow going for the political upshots garnered, but for Weinstein's more general audience in ancient philosophy and for those whose teaching and research focuses closely on the city-soul analogy in the Republic, this book will surely be rewarding.