Levi ben Gershom (Gersonides) has emerged in recent years as one of the most significant and comprehensive medieval Jewish philosophers. He was quoted constantly (even if only to be criticized) and, through the works of Ḥasdai Crescas and others, his ideas influenced such thinkers as Leibniz and Spinoza. The Gersonidean corpus is wide-ranging and includes halakhic works, biblical exegesis, mathematics, science and astronomy, and philosophy. While most of the attention has focused on his metaphysical and scientific works, recent scholars have turned towards Gersonides's more “Judaic” and ethical works, found primarily in his commentaries on Scripture. Despite the popularity and influence of these commentaries in Jewish biblical exegesis, they have received far less attention from scholars of Jewish philosophy. Charles Touati was the first to highlight the significance of these works, but in the past decade other scholars (Menachem Kellner; David Horwitz; Assael Ben-Or) have begun groundbreaking work in the area. Alexander Green's volume belongs in this latter category, and provides an innovative and important study of Gersonides's moral and political thought.
Gersonides's biblical commentaries were written after he finished Wars of the Lord (Milḥamot ʾAdonai). These include his commentary on the Torah, as well as on other books of Scripture (Job, Song of Songs, Ecclesiastes, etc.), which often draw from or complement the philosophical material in Wars of the Lord. Gersonides's commentary on Scripture is one of the first by an Aristotelian philosopher to provide a successive commentary on most of the Bible. Why didn't Gersonides provide a supercommentary of Averroes's Nicomachean Ethics and Republic? That ethics, which is based on convention and opinions, is not a precise science like mathematics was noted already by Aristotle in his ethical works. Green suggests that perhaps Gersonides followed Aristotle's line, and introduced a narrative style that exemplifies the contingency and variability of ethical discourse (5).
Gersonides's ethical theory is couched in the context of examples, or lessons, of the lives and actions of particular individuals, rather than in a scientific commentary (4). Using biblical proof texts, he derives practical lessons (toʿalot) meant to teach particular virtues. As Green notes, these lessons represent “practical maxims that enable one to achieve perfection” (6). They offer philosophical insights into three main areas: the commandments, moral and political philosophy, and theoretical philosophy that includes both metaphysics and natural science.
In chapter 2, Green emphasizes that for Gersonides the primary goal of the practical intellect is self-preservation. Green is concerned to distinguish between Maimonides's and Gersonides's ethical theories. He argues that, like Maimonides, Gersonides focuses on the mean as the basis for ethics, while adding two new virtue categories: virtues of self-preservation and virtues of altruism. Both Aristotle and Maimonides emphasize the doctrine of the mean as part of their ethical theory: on this model, virtues represent a balance between extremes. Maimonides adopts most of Aristotle's virtues. In his Eight Chapters, for example, he describes many of the moral virtues as lying in the mean between excess. Gersonides, however, introduces a new set of materialistic virtues that emphasize the importance of maximizing one's physical needs—endeavor, diligence, and cunning in crafting stratagems—that are described at great length in his toʿalot (33). All three virtues, according to Green, are “physio-biological capacities rooted in the human imagination that humans can perfect to maximize physical self-preservation” (33). Green provides a detailed elaboration of these three virtues as reflected in a variety of biblical contexts.
Green makes the interesting point that in contradistinction to Maimonides, who in the Guide for the Perplexed denigrates the body and physical existence of humans, Gersonides claims physical preservation to be a “moral necessity” (35), especially in light of the whims of fate and fortune (34). Abraham, who brought all his possessions with him from Canaan to Egypt, may serve as an example. Gersonides extols Abraham's actions in passing off his wife Sarah as his sister, claiming that “a person must protect his possessions with as much diligence [ḥariẓut] as possible” (42).
Chapter 3 focuses on altruism and the beneficent virtues, again against the backdrop of Maimonides's emphasis on the passive or indirect effect of altruistic actions. Green contrasts Gersonides's conception of “active altruism” with the views of Aristotle, Saʿadiah Gaon, and Maimonides, and argues that in contradistinction to Maimonides, Gersonides presents a “universal ethics of enlightenment aimed at imitating God's altruistic attributes … in a way that is not restricted by political boundaries” (69). Chapter 4 compares Maimonides and Gersonides on the role of justice as ordering “the value of competing goods and the role of the individual to independently deliberate” (91). Gersonides (again, in contrast to Maimonides) will claim that divine law does not impose a “standard of political justice” but leaves space to individuals to deliberate independently of the law. Green focuses on three sets of competing goods—property, peace, and divine law—to demonstrate Gersonides's model of deliberation and choice. In this important analysis, Green suggests that Gersonides may have been influenced by ethical discussions with his scholastic contemporaries, who themselves were wrestling with issues of natural law and morality (105).
The fifth and final chapter develops further the ethics of divided political institutions, pitting king, priest, and prophet against one another. Green claims (following Esti Eisenmann and in contrast with other recent scholars) that Gersonides is an independent political thinker who formulated his own political philosophy, one in which the prophets “serve as a vital check on the power of both institutions” (125).
In short, Green's study of virtue ethics in Gersonides provides an important and fresh study of his contribution to the moral sphere. Green's work is accessible and serves as a vital introduction to Gersonides's moral and political thought; it should be required reading for all scholars wishing to broaden their understanding of fourteenth-century Jewish philosophy.
