Judaism Within the Limits of Reason

The Littman Library of Jewish Civilization


September 3rd, 2015



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Gersonides (1288-1344), known also as Ralbag, was a philosopher of the first rank as well as an astronomer and biblical exegete, yet this is the first English-language study of the significance of his work for Jewish thought. Seymour Feldman, the acclaimed translator of Gersonides' most important work, The Wars of the Lord - a complete philosophical system and astronomical encyclopedia - has written a comprehensive picture of Gersonides' philosophy that is both descriptive and evaluative. Unusually for a Jewish scholar, Gersonides had contacts with several Christian notables and scholars. It is known that these related to mathematical and astronomical matters; the extent to which these contacts also influenced his philosophical thought is a matter of some controversy. Unquestionably, however, he wrote a veritable library of philosophical, scientific, and exegetical works that testify not only to the range of his intellectual concerns but also to his attempt to forge a philosophical-scientific synthesis between these secular sciences and Judaism.
Unlike many modern scientists or philosophers, who either scorn religion or compartmentalize it, he did not see any fundamental discrepancy between the pursuit of truth via reason and its attainment through divine revelation: there is only one truth, with which both reason and revelation must agree. As a philosopher-scientist and biblical exegete Gersonides sought to make this agreement robustly evident. While philosophical and scientific ideas have progressed since Gersonides' time, his work is still relevant today because his attempt to make prophecy and miracles understandable in terms of some commonly held philosophical or scientific theory is paradigmatic of a religion that is not afraid of reason. His general principle that reason should function as a 'control' of what we believe has interesting and important implications for the modern reader. Indeed, some of his basic arguments are favoured by many contemporary thinkers who attempt to incorporate modern science into their religious belief system.
He was not afraid to make religious beliefs philosophically and scientifically credible; one could say that he pursued an 'ethics of belief' in that he held that there are constraints to what is believable, especially in religion. In this respect he was a precursor of Kant and Hermann Cohen: Judaism is or should be a religion of reason.


'Will be welcomed by all serious students of Jewish thought [...] definitely worth the effort. Recommended.'
Barry Dov Walfish, AJL Reviews

'An extremely welcome, important, and long-overdue addition to the literature ... the first monograph in English to look at a broad range of Gersonides' philosophical ideas [...] Feldman does a terrific job of exposition and philosophical examination. His analyses are clear and accessible without being over-simplified. He does great justice to Gersonides' thought, as well as to its historico-philosophical contexts. The book is also a pleasure to read. This is just the kind of study on Gersonides that we have long needed, and one can only hope'Without question Feldman presents a superb summary of the totality of Gersonides' Jewish philosophy in a single volume that is carefully reasoned and clearly written. Certainly no philosophers or intellectual historians of medieval thought can consider themselves academically literate without at least some familiarity with the writings of Gersonides, and Feldman does a better job than anyone else in providing a reliable foundation for that minimal philosophical knowledge. His book should become a standard text.'
Norbert Samuelson, H-Judaic

'An impressive achievement [...] a useful book for anyone interested in medieval Jewish philosophy, either specialist or novice.'
Jewish Book World

'A succinct conspectus of Gersonides' positions on the pivotal issues of medieval Jewish philosophy and the arguments he offers in their favour [...] Feldman's style is lucid and engaging. In the course of contrasting Gersonides with Maimonides, who, Gersonides felt, begged some important questions, Feldman offers some valuable insights from which the myriad of Maimonidean specialists may yet profit.'
Y. Tzvi Langermann, Journal of the History of Philosophy

'A comprehensive survey [...] reflects a deep and thorough acquaintance with the philosophical, as well as with the Jewish tradition. The book therefore is both an inviting introduction for students and an important contribution to research that should be read by historians of Jewish philosophy.'
Ruth Glasner, Shofar

‘A comprehensive look at one of the most formidable Jewish philosophers.’
Ben Rothke, Times of Israel

Author Information

Seymour Feldman taught philosophy at Rutgers University from 1963 until his retirement. He is the author of 'The Wars of the Lord' by Levi ben Gershom (Gersonides) (1984–99) and 'Philosophy in a Time of Crisis: Don Isaac Abravanel–Defender of the Faith' (2003), and editor of both Spinoza's 'The Ethics, Select Letters and Treatise on the Emendation of the Intellect' (1992) and his 'Theological-Political Treatise' (second edition, 1998).

Table of Contents

Table of Contents
Section TitlePagePrice
Cover 1
Half Title2
Title Page4
Note on Transliteration12
Note on Sources14
1. Introduction: Life and Works16
Philosophical Environment22
Motives and Methods29
2. The Story of Creation43
Gersonides’ Cosmological Conundrums43
The World Is Not Eternal: It Was Created46
The World Is Indestructible59
Creation Ex Nihilo Is False63
Philosophical Cosmology and Biblical Exegesis70
3. God and his Attributes74
How Can the Existence of God Be Proved?74
How Can We Speak about God?84
4. Divine Omniscience96
Rabbi Akiva’s Dilemma96
Gersonides’ Solution to Rabbi Akiva’s Dilemma97
5. Divine Providence119
The Case for Individual Providence119
Why Do the Innocent Suffer?130
The People of Israel and Divine Providence139
6. Divine Omnipotence146
‘Is Anything Impossible for the Lord?’146
Gersonides’ Theory of Miracles149
7. Prophecy160
What Does Philosophy Have To Do with Prophecy?160
Gersonides’ Theory of Prophecy162
Moses, the ‘Super-Prophet’174
Are Prophets Infallible?181
8. Humanity and its Destiny187
Philosophical and Religious Background187
Gersonides’ Theory of the Intellect195
The Immortality of the Intellect200
Gersonides’ Critique of Immortality as Conjunction with the Agent Intellect204
9. The Torah213
Do We Need the Torah?213
How Should We Read the Bible?223
The Commandments231
Is the Torah Immutable?236
10. Conclusion239
Works by Gersonides252
Primary Sources253
Secondary Sources256