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Andrew V. Kudin

Jewish Philosophy

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Jewish philosophy cannot be defined by the identity of its authors. Spinoza belongs to its history even where he breaks with the authority of Jewish law, while many philosophers of Jewish origin have written works with no meaningful relation to the Jewish intellectual tradition. A definition based on philosophical defenses of Judaism fails from the other side. Some of the tradition’s most important figures challenged inherited doctrines, transformed the meaning of revelation, or questioned whether philosophy and religious tradition could finally be reconciled.

Its continuity lies in a demanding tension. Jewish philosophy arose when rational inquiry entered a world structured by revelation and covenant, law and interpretation, worship and communal memory. The field was occupied before philosophy arrived. Philosophy met claims that bound the person who received them.

The encounter altered the meaning of philosophical understanding. Knowledge was rarely allowed to remain self-contained. A conclusion about God reshaped what could truthfully be said about God. Interpreting a commandment meant entering an argument about obligation. Whoever asked whether human beings are free was also asking whether praise, blame, repentance, and judgment make sense. In Jewish Philosophy and Kabbalah, I put the principle this way: what is understood becomes what is required.

Contents

What Is Jewish Philosophy?

Revelation and Rational Inquiry

Jewish philosophy took shape where inherited revelation met rational inquiry, and the encounter was never finally resolved. That unresolved meeting is part of what keeps the tradition intellectually alive. Reason asks for demonstration. It distinguishes what follows from what, rejects contradiction, tests claims against experience, and demands that words such as God, creation, freedom, and justice mean something sufficiently precise to be argued about. Revelation enters the discussion with a different kind of authority. It does not first ask whether the hearer has been persuaded. It speaks and commands, narrates and remembers, and establishes a relation before philosophy has decided how such a relation should be understood.

The history of Jewish philosophy refuses both familiar stories: the long contest in which reason gradually defeats revelation, and the defensive exercise in which revelation repeatedly silences reason. Saadia believed that reason and revelation ultimately converge, although revelation teaches what reason alone cannot derive. Maimonides pushed philosophical demonstration further and, in the same movement, drew severe limits around what could be said of God. For Judah Halevi, the question was whether the God reached through philosophical argument was the God to whom one could pray. Spinoza separated philosophy from Scripture and rewrote the terms of the argument.

As Jewish thinkers entered different philosophical cultures, the vocabulary of the questions changed. Greek metaphysics, Arabic kalām (rational theology developed in the Islamic world), Aristotelian science and medieval Islamic philosophy, the German Enlightenment, neo-Kantianism, phenomenology, and modern ethics all entered the conversation at different moments. The conversation remained recognizably Jewish because philosophical inquiry continued to meet covenant, text, practice, and memory as prior claims.

Knowledge and Obligation

The bond between thought and obligation stands out most clearly against the classical ideal of the contemplative life. A philosopher may seek truth because knowing is itself the fulfillment of the intellect. Jewish philosophical traditions repeatedly refuse to leave matters there. If God is incorporeal, the anthropomorphic language of Scripture and prayer demands interpretation. A world that is created, and did not have to be, changes what human dependence means. Grant that the will is free, and judgment and repentance become intelligible; deny it, and an entire moral structure is destabilized. If revelation contains law, discovering what a text means has consequences beyond the satisfaction of having interpreted it correctly.

Jewish philosophers do not reach a common conclusion, and they do not derive obligation from a single source. What recurs is the refusal to seal philosophical truth off from existence. The knower is implicated in what is known.

Before Philosophy: Scripture, Covenant, and Interpretation

The Hebrew Bible as a Source of Philosophical Questions

The Hebrew Bible is not a philosophical system. It proceeds without definition or demonstration and organizes its teaching around none of the problems that later philosophers would identify as metaphysics, epistemology, ethics, or philosophy of religion. It narrates and commands, mourns and praises, condemns and remembers, and preserves voices that do not always agree with one another.

The philosophical questions came later.

Philo, Saadia, Maimonides, and later Jewish thinkers read philosophical problems into a corpus that had not been composed as a work of philosophy. That is why their labor became philosophically creative. They inherited texts in which God speaks with a hand and an arm, though later philosophical theology would insist on divine incorporeality. Creation was narrated, with no technical metaphysics behind it, and commands were issued before anyone had built a philosophical theory of obligation able to explain why a command binds. Their inheritance also paired Job with Deuteronomy, Proverbs with Ecclesiastes: texts whose differing voices resisted reduction to one doctrinal formula.

The covenant between God and Israel was historical, normative, and capable of breach. Nowhere was it presented as an abstract relation between first cause and contingent being. A covenant could be entered and violated, remembered and renewed, and it could be interpreted. Philosophy would later ask what kind of divine being could enter such a relation and what kind of human freedom such a relation presupposed.

The prohibition of images left a problem of its own. It begins as a command concerning worship, with no metaphysical proof of incorporeality behind it. Yet the tension between a God who cannot be represented and a Scripture filled with descriptions of divine action would eventually become one of the central problems of medieval Jewish philosophy.

Contradiction itself persisted. Biblical literature preserved its competing voices. The moral economy of reward and punishment stands beside the suffering of Job; confidence in the rewards of wisdom sits alongside Ecclesiastes’ insistence that the wise and the fool share the same death. By leaving these tensions standing, the canon made interpretation unavoidable.

Interpretation Before Philosophy

Long before Jewish thinkers adopted the conceptual languages of Plato, Aristotle, or Muslim theologians, rabbinic Judaism had developed a culture in which authoritative texts generated argument and kept it in motion. The Oral Torah named the claim that revelation was not exhausted by the written text. Its life continued through transmission and interpretation. The Mishnah preserved rejected opinions beside accepted ones; the Talmud turned disagreement into a literary form. Revelation and human interpretation were joined without being reduced either to simple submission or to unrestricted freedom.

Rabbinic argument was not yet philosophy in the systematic sense. It usually asked what followed from a verse, which precedent governed a case, or how a command applied under particular circumstances. It did not normally begin by asking whether God exists, what substance is, or whether freedom can be reconciled with divine knowledge. Yet it established something Jewish philosophy would never escape: a revealed text requires a human reader, and textual authority does not abolish the responsibility of interpretation.

The philosophical vocabulary arrived later, from outside, and the first language it spoke was Greek. The Torah had been translated into the language in which Plato was read. With that translation, inherited revelation entered a conceptual world capable of asking questions the biblical writers had never formulated. The next decisive figure was Philo of Alexandria, a Jewish thinker reading Moses in Greek, who attempted, for the first time on a large scale that survives, to hold philosophical reason and the authority of Torah in the same hand.

From Moses in Greek to Jewish Philosophy in Arabic

Jewish philosophy found its philosophical language outside Hebrew. Its first great experiment ran in Greek; its medieval transformation unfolded largely in Arabic. Translation was only the surface. Each language carried a philosophical culture with it, and Jewish thinkers had to decide what could enter the tradition untouched, what had to be recast, and what would change the meaning of revelation if accepted on its original terms.

Philo read Moses through categories forged by Greek philosophy. Later, Saadia argued inside a world shaped by Islamic theology, and Ibn Gabirol wrote a Neoplatonic metaphysics whose Jewish origin dropped out of sight for centuries. Baḥya ibn Paquda drew on Islamic ascetic and Sufi traditions to articulate an interior discipline of obligation. Judah Halevi mastered philosophical argument well enough to expose what he believed it could never supply. By the time of Maimonides, Aristotle, the Muslim philosopher al-Farabi (c. 870–950), Arabic kalām, biblical exegesis, rabbinic law, and the inherited demands of Jewish life could live in the same mind.

Philo of Alexandria: Moses in Greek

Almost everything Philo of Alexandria (c. 20 BCE–c. 50 CE) wrote was commentary on the Torah. No independent philosophical system came first, with Scripture combed afterward for illustrations. The biblical text remained the object of interpretation, and philosophy supplied the instruments for opening its depths.

Allegory made the operation possible. Abraham’s departure could become the intellect’s movement away from false belief, Sarah and Hagar could describe stages of education, Egypt could stand for the body, and the exodus for liberation from its grip. Beneath the history and law of the written text, Philo found an account of the cosmos and the soul.

The danger of such reading was obvious even in his own time. If circumcision has an inward meaning, why retain the physical act? If the Sabbath signifies the soul’s repose, why continue to observe the seventh day? Philo refused the inference. The discovery of a deeper meaning did not cancel the practice through which the commandment had entered Jewish life. Interpretation could enlarge the meaning of obedience. Declaring obedience obsolete lay beyond its power.

His sources were many. Plato furnished much of the metaphysical architecture, Stoicism the psychology and ethics, and Aristotelian concepts came in wherever they proved useful. Philo treated none of these schools as a court before which the Torah had to defend itself. The Timaeus, for example, offered an intelligible pattern according to which the cosmos was ordered. Genesis required a creator whose act was free. Philo brought the two together by placing the Forms within the divine intellect, where they became the intelligible content of the divine mind and ceased to be an eternal realm standing beside God.

Philo’s theology then met a harder problem. God exceeds the reach of the human intellect, yet this same God creates, governs, and speaks. Philo’s Logos (literally “word” or “reason”) occupies that distance under a succession of images—pattern, instrument, intermediary—without settling into a single doctrine. More consequential for later Jewish philosophy was the distinction beneath those images: human beings may know that God is; they cannot know what God is.

The historical irony is severe. Rabbinic literature did not preserve Philo. Christian readers did, because the Church found uses for his writings; the Jewish philosophical tradition that later confronted many of the same problems developed without direct access to his work. The encounter of Moses and philosophy therefore had to be staged again.

This time the language would be Arabic.

Saadia Gaon: Reason and Revelation

Saadia Gaon (882–942) wrote for readers whose inherited faith had become intellectually vulnerable. Doubt, as he met it, called for argument; demanding more obedience would have settled nothing. The Book of Beliefs and Opinions gave rabbinic Judaism its first systematic philosophical theology. Its setting was the Arabic-speaking world, especially the traditions of kalām. Saadia entered disputes being conducted among Muslim theologians, Christians, dualists, skeptics, and other schools of thought. Jewish teaching now stood in a common arena of argument, where assertion by itself was insufficient.

Saadia trusted reason deeply. The intellect, working without revelation, could establish that the world had been created, that it had a creator, that the creator was one, and that human beings stood under moral obligations. Revelation left those conclusions standing and supplied what reason could never derive by itself: the concrete shape of commandments whose content depends upon having been commanded.

The distinction carried a lasting difficulty. Once some commandments are justified by reasons available to every rational person, the remaining commandments invite a different kind of scrutiny. Why this act, this day, this prohibition? A philosophical defense of revelation had opened a question that revelation by itself had no need to ask.

The same pattern marks Saadia’s defense of the Oral Torah against the Karaites, Jewish communities that rejected the binding authority of rabbinic oral tradition and claimed Scripture as their sufficient guide. Scripture taken in isolation cannot tell a community how to perform everything it commands. It forbids work without providing a complete theory of what counts as work and prescribes practices whose details appear nowhere in the written text. The words themselves arrive through a transmitted language. A reader who rejects every tradition in order to obey Scripture alone discovers that reading has placed him inside a tradition. With Saadia, reason becomes indispensable to the defense of revelation and capable of asking questions no defense can permanently contain.

Ibn Gabirol, Baḥya, and Judah Halevi: Competing Uses of Philosophy

Solomon ibn Gabirol (c. 1021–c. 1058) shows how far Jewish philosophy could move from explicit Jewish reference. His Fons Vitae has no room for Torah, rabbinic citation, Israel, covenant, or commandments. Its world is Neoplatonic. Everything below God, including spiritual substances, is composed of matter and form; Divine Will mediates between the unknowable First Essence and the ordered levels of reality.

Translated from Arabic into Latin, the work entered Christian scholastic philosophy under the name Avicebron. Its Jewish authorship was forgotten; nothing in the argument gave it away. The same man wrote Keter Malkhut, one of the great works of Hebrew religious poetry, later incorporated into Jewish liturgical life. The contrast resists an easy definition of Jewish philosophy. A philosopher does not become Jewish merely by citing Jewish sources, and leaving them uncited erases nothing of the tradition in which he stands.

Baḥya ibn Paquda, writing in eleventh-century Spain, moved in another direction. His Duties of the Heart starts from an imbalance he perceived in religious practice. Jewish law had elaborated the duties of the body with immense precision, while the obligations of the inner life received far less systematic attention. Baḥya turned toward intention and trust, humility and self-examination, sincerity and love. His scheme of spiritual progress, and a good part of its vocabulary, owes unmistakable debts to Islamic ascetic and Sufi literature. Those materials were worked into a Jewish structure governed by Scripture, rabbinic teaching, and commandment. Obligation now reaches into the inner life. Conduct alone is insufficient; a person must examine his intentions, his trust, his loves, and what he owes for what he has received.

Judah Halevi (c. 1075–1141) distrusted the philosophical project at a deeper level. The Kuzari lets the philosopher make the first attempt to persuade the Khazar king, and the philosopher offers a God worthy of metaphysics: perfect, immutable, intelligible, untouched by the contingencies of human life. Halevi has no need to show that this God was badly demonstrated. He asks what would follow if the demonstration succeeded entirely, and the answer, in his judgment, is still too little. A metaphysical first principle falls short of the God of Abraham, Isaac, and Jacob, the God met through a particular history, covenant, command, and people. The philosopher offers a conclusion. The king is looking for a relation.

That objection reaches past any dispute over proofs. Philosophy seeks what is universally true; revelation enters history in particular events and addresses particular human beings. Halevi refuses to assume that the second is an imperfect version of the first. By the twelfth century Jewish philosophy held sharply different possibilities, from metaphysics almost stripped of historical particularity to a challenge to philosophy’s own jurisdiction. Maimonides took up this inheritance and sharpened its tensions.

Maimonides and the Limits of Philosophical Knowledge

Reason, Revelation, and the Perplexed Reader

The Guide for the Perplexed begins with a wounded reader.

He knows too much to accept every scriptural expression literally and belongs too deeply to the tradition simply to walk away from it. He has studied philosophy and encountered demonstrations that seem incompatible with the language in which he learned to speak of God. If he silences his intellect, the contradiction remains inside him. If he abandons revelation, the intellectual victory costs him the world from which the question arose.

Moses Maimonides (1138–1204) wrote for that condition. He also made the book itself difficult enough to reproduce it. The Guide warns its reader that apparent contradictions have been planted deliberately, that important propositions may appear once and away from the place where one expects them, and that teachings traditionally restricted to a single student have been committed to writing under concealment. The centuries of disagreement over what Maimonides “really meant” belong partly to the architecture of the work itself.

His treatment of creation shows how far he is prepared to go. Maimonides presents Aristotle’s arguments for the eternity of the world in their full strength and finds them persuasive without accepting them as demonstration. Had eternity been demonstrated, he says, Genesis would have required reinterpretation, just as scriptural descriptions of God’s body require it once incorporeality has been established.

No literal meaning of Scripture is shielded from demonstrated truth. Interpretation must move when reason genuinely proves its case. Creation stands because Aristotle never proved eternity; revelation speaks where demonstration runs out.

Negative Theology: What Can Be Said About God?

The limit tightens in Maimonides’ treatment of divine attributes. A positive attribute seems innocent until divine unity is taken with full seriousness. If God is wise in the way a person is wise, wisdom appears as something predicated of a subject. The distinction between possessor and attribute has entered the divine essence. Maimonides will not pay that price.

Negation becomes the safer path, the via negativa or negative way. God is not corporeal, not divisible, not subject to change, not dependent. Each negation removes an error without claiming possession of the divine essence. Progress takes a peculiar form: the intellect advances while the field of permissible description contracts.

Elliot R. Wolfson reads this apophatic dimension of Maimonides as the point where knowledge confronts its own inability to seize its object. Negation reaches a limit at which the intellect recognizes the inadequacy of the forms through which it has tried to speak of God.

Maimonides never hands the work over to mystical intuition. Reason strips away one representation after another until it meets a God whom the intellect cannot turn into an object like any other object of knowledge. Silence, once the mere absence of speech, now carries philosophical weight: it is what remains when language has been disciplined enough to recognize the damage done by careless praise.

Religion, however, must still speak. Prayer cannot be conducted entirely by negation. Scripture is thick with verbs and names, images, anger and mercy, descent and presence. The God whom philosophical theology refuses to describe is addressed every morning, and the tension never dissolves inside Maimonides. Later readers pick it up where he left it.

Parable, Imagination, and the Problem of Speaking the Unspeakable

Figurative language fills the space pure negation cannot. Maimonides rejects literal anthropomorphism with unusual severity, but he does not imagine that human beings can be educated without images. Scripture speaks of hands, faces, movement, and anger because its language must reach people whose thought begins in embodied experience. The philosopher learns to strip away the literal image while keeping what it was meant to teach. The parable carries an epistemic burden: it conceals because direct statement would mislead, and it reveals because complete silence would teach nothing.

Imagination makes the case harder still. Maimonides repeatedly distrusts it where it competes with intellect, yet prophecy ordinarily requires it. The prophet receives intellectual content through a human faculty capable of clothing that content in images, forms, and language. Even a truth that exceeds representation enters public life through representation.

Wolfson’s account of apophasis sharpens the difficulty. In the introduction to Apophasis and Envisioning the Invisible, he calls the apophatic a gesture of “speaking-not” (p. 1): speech that tries to say what ordinary predication cannot secure. The unsayable does not become available merely because language admits defeat; it forces speech to qualify, retract, negate, and expose its own limits.

Take away the image and the mind goes on imagining. A language free of predicates stays out of reach, however firmly literal ones are refused. Revelation must cross the distance between what the intellect can purify and what human beings can actually hear.

The Guide inhabits that distance. Its parables and concealments, its negations and carefully managed contradictions, are the philosophical work itself and no literary decoration laid over it. Silence never becomes the final solution. It protects transcendence, but a tradition built from Torah, teaching, prayer, and interpretation cannot remain silent. The difficulty has to be lived in language.

The Legacy of Maimonides

The generations after Maimonides inherited the questions without a settlement. His account of God made ordinary religious language philosophically dangerous. His treatment of creation let demonstrated truth govern biblical interpretation more radically than many readers were prepared to accept. His theory of prophecy brought revelation into contact with psychology and intellectual perfection, and his search for reasons behind the commandments refused the safety of declaring divine law inaccessible to human understanding.

Translations of the Guide carried the work into communities that did not share the Arabic philosophical culture in which it had been written. Bans were issued and answered by counter-bans; Maimonides’ defenders and opponents fought over the limits of philosophy, scriptural interpretation, resurrection, human perfection, and religious authority. The dispute outlived the men who began it.

The controversy did not sort medieval Judaism into rationalists and anti-rationalists once and for all. Naḥmanides (1194–1270) could oppose important features of Maimonidean philosophy and still become a central transmitter of Kabbalah. Philosophical concepts entered mystical texts; mystical doctrines responded to philosophical problems. Even resistance to Maimonides often had to take up questions in the form he had given them.

Maimonides left Jewish philosophy with a God about whom the intellect had learned restraint, a Scripture that had to withstand philosophical demonstration, and a conception of human perfection with practical consequences. Reason and revelation remained unreconciled. His achievement was to make visible what any future reconciliation would have to explain: the limits of language, the authority of demonstration, and the place of revelation once philosophy had claimed the right to interpret it.

Law, Interpretation, and the Problem of Obligation

Command and Moral Reason

Jewish philosophy cannot relegate law to the margins, because the question of what a human being ought to do appears before philosophy has supplied a theory explaining why. The rabbinic account of Sinai puts the problem in its sharpest form. Israel accepts the covenant before hearing its full content: it will do, and then hear. Philosophical deliberation normally assumes the opposite order, in which one examines an obligation before consenting to it. The Talmud preserves both the praise of this response and the objection to it, leaving open a question that Jewish philosophy would repeatedly confront: what makes a command binding?

If human reason can see that murder is wrong, divine prohibition seems to confirm an obligation that exists independently of the command. If murder becomes wrong only because God prohibits it, morality risks becoming arbitrary. Saadia divided the problem. Some obligations—justice, truthfulness, gratitude, the prohibitions against murder and theft—are accessible to the intellect. Others depend upon revelation for their specific content.

Maimonides goes further. He refuses to regard divine law as the unexplained product of a will whose wisdom consists simply in being obeyed. The commandments have purposes even when those purposes remain hidden. He reads some laws historically, asking what practices they opposed and what kind of people they were intended to form. His account of sacrifice follows from this approach: a people accustomed to sacrificial worship could not simply be commanded into an entirely different religious psychology, so an existing form was redirected and disciplined. Naḥmanides rejects the argument sharply and reads sacrifice kabbalistically, as an act below with consequences above.

One commandment could therefore appear as rational legislation, historical pedagogy, covenantal obedience, or an act whose consequences exceed the visible world. Jewish thought preserved these possibilities without reducing them to a single theory. Nor did legal correctness exhaust moral judgment. Rabbinic sources could demand exact observance and still condemn the person who used the letter of the law to cover conduct that was formally defensible and morally corrupt. Abstract moral principle is only one way obligation reaches the individual; law, inherited practice, circumstance, precedent, and human judgment converge when someone must decide what fidelity actually requires.

Law as an Interpretive Practice

Rabbinic law carries interpretation into the structure of obligation itself. The old prohibition against writing down the Oral Torah eventually had to yield when the survival of the tradition required written preservation. The change did not treat inherited authority as disposable. It arose from the opposite conviction: fidelity to the substance of a tradition may require altering the form in which that tradition is carried.

Written rules also survive the circumstances in which they were formulated. New cases arrive; words remain. Interpretation allows inherited texts to govern situations their authors never encountered, which means that authority depends on human judgment even while constraining it. Text, precedent, institutional practice, and communal memory set limits on admissible readings, but no code can anticipate every future case.

The familiar number of 613 commandments suggests a closure that practical Jewish law never possessed. The tradition produced no universally accepted enumeration, and legal questions were not decided by consulting such a list. Halakhah (Jewish law and legal practice) developed through Talmud, commentary, codes, custom, and responsa (rabbinic rulings written in answer to concrete legal questions). A legal order presented as bounded and given nevertheless generated new determinations through the practices by which it was transmitted.

Jewish Philosophy and Kabbalah: A Boundary That Never Fully Holds

Philosophy and Mysticism in the Same Medieval Setting

Modern academic classifications draw a clear line between Jewish philosophy and Kabbalah, but the medieval evidence is less orderly. Sefer ha-Bahir entered circulation in Provence within a generation of the Guide for the Perplexed. The controversies surrounding Maimonides and the appearance of early Kabbalah unfolded in overlapping communities. Naḥmanides was both a major rabbinic authority and a kabbalist. Legal reasoning, philosophical theology, biblical exegesis, and esoteric teaching belonged to the same learned culture.

Maimonidean philosophy and Kabbalah nevertheless speak very differently about God. Maimonides removes positive predicates from the divine essence with relentless rigor. Kabbalistic texts build symbolic accounts of the sefirot, the ten modalities through which Kabbalah describes divine manifestation, and of concealment, abundance, union, exile, rupture, and repair. Their methods are distinct, and their theological claims can collide. Yet they return to related problems: how transcendence can stand in relation to a finite world, how language can refer to what exceeds representation, and what becomes of human action once that relation has been understood.

On the last question Kabbalah goes furthest. Prayer, study, commandment, and intention are described as affecting relations within the divine order itself. In the sefirotic system, action below awakens response above. Cosmology becomes inseparable from practice. The kabbalist’s knowledge of the divine world enters the act he performs and changes what that act means.

Maimonides, Apophasis, and the Kabbalistic Response

The connection is clearest in negative theology. Maimonides protects divine unity by stripping positive attributes from the divine essence. Knowledge proceeds through negation until the philosopher reaches the point at which language itself becomes suspect. Kabbalistic texts inherit the problem and refuse to stop where Maimonides stops. They construct intricate symbolic descriptions of divine manifestation and still place the ultimate source beyond ordinary comprehension.

Wolfson begins the historical movement of Apophasis and Envisioning the Invisible with Maimonides because later kabbalists were deeply affected by the Maimonidean via negativa and felt compelled to answer it. That continuity also supports his challenge to a scholarly division that treats philosophy and mysticism as sealed intellectual territories.

The kabbalistic answer is no simple restoration of what Maimonides removed. Maimonides narrows theological speech until silence commands authority. Kabbalah lets symbolic language multiply, and the symbols speak because direct predication fails; they leave that failure standing. No symbol is identified with what it finally signifies, and the ultimate divine source stays closed to literal description.

Their accounts of commandment diverge accordingly. Maimonides searches for purposes that explain how law educates, restrains, redirects, and perfects human beings, while kabbalistic systems can assign the same act consequences within the divine structure itself. The dispute between Maimonides and Naḥmanides over sacrifice shows the result: interpretation changes what kind of act is being performed.

For the cosmology, texts, and later development of these traditions, see the separate article on Kabbalah. Placing philosophy on one shelf and mysticism on another obscures the arguments they shared.

After Maimonides: Gersonides and Crescas

Maimonides did not end the medieval argument. Two of his most important successors reopened different parts of his settlement and exposed how unstable some of its compromises had been. Levi ben Gershom, known as Gersonides (1288–1344), was a philosopher, biblical commentator, mathematician, and astronomer working in Provence. In The Wars of the Lord he refused Maimonides’ decision to place the relation between divine knowledge and human freedom beyond human comprehension. If God infallibly knows a future choice as this particular choice, Gersonides argued, the choice cannot remain genuinely open. He preserved freedom by qualifying omniscience: God knows the order of possibilities and everything that follows necessarily from it, while contingent particulars are known as contingent rather than as fixed future facts. On creation he was equally willing to depart from Maimonides, arguing that God formed the world from pre-existing formless matter.

Ḥasdai Crescas (c. 1340–1410/11) attacked a different foundation. Light of the Lord challenges the Aristotelian physics on which many medieval proofs of God had depended. Crescas defended the possibility of a vacuum and of actual infinity and rejected assumptions about space and motion that Maimonides had inherited from Aristotle. His target was the dependence of theology on philosophical premises that could fail.

His reconstruction also changed the account of human perfection. Where the Maimonidean tradition gave the intellect a privileged place, Crescas placed love closer to the center. The commandments attach the human being to God through love, a form of relation open to those who will never master philosophical demonstration. On freedom he accepted a stronger role for necessity and the consequences that followed from it. Spinoza would later read Crescas closely and cite him by name.

Spinoza and the Question of Belonging

Baruch Spinoza (1632–1677) changes the terms of the argument. The old question was how far philosophy can proceed before revelation corrects it; he asks whether the two are engaged in the same task at all. The Theological-Political Treatise begins from a principle that would become commonplace only much later: Scripture must be interpreted through its language, composition, historical circumstances, and transmission, and no doctrine established elsewhere may be forced upon it. Spinoza develops hints found in Abraham ibn Ezra (c. 1089–1167), the medieval biblical commentator, and treats the biblical text as a document with a history. Philosophy and Scripture are then assigned different domains. Philosophy seeks truth; Scripture seeks obedience, justice, and charity. A person who cannot follow a demonstration can still live justly, and philosophical truth needs no biblical authority to be true.

Saadia had expected reason and revelation ultimately to converge. Maimonides allowed demonstration to govern interpretation while still requiring Torah and philosophy to coexist within a single religious and philosophical life. Spinoza reduces much of that tension by giving them separate purposes.

The consequences extend far beyond biblical interpretation. The God of the Ethics does not deliberate. He selects no world from among possible ones, never suspends nature, answers no prayer, and issues no command at a moment in history. Everything follows from the necessity of the divine nature. What Maimonides had protected by preserving the contingency of creation—miracle, prophecy, and a law given in time—loses the metaphysical ground on which it had stood.

Halevi’s old objection returns in altered form. The philosophers’ God, he had argued, was the conclusion of an argument and therefore not the God to whom Israel prayed. Spinoza accepts much of the description and denies that it constitutes a defect. A God worthy of philosophy does not become less divine because He cannot be persuaded, appeased, or moved by human desire.

Is Spinoza a Jewish Philosopher?

Biography cannot settle the question. If Jewish birth were sufficient, every work written by a philosopher of Jewish origin would belong to Jewish philosophy. Expulsion settles nothing either; an argument does not vanish from an intellectual tradition because its author has been cast out of a community.

The thinkers he argues against reveal the stronger connection. He takes on Maimonides by name. From Crescas he inherits part of the assault on Aristotelian physics while abandoning the theological reconstruction Crescas intended. His biblical criticism develops problems present within Jewish exegesis, and his conception of God answers questions medieval Jewish philosophy had spent centuries trying to contain.

Yet covenant no longer provides the framework of philosophical inquiry. Revelation possesses no privileged access to metaphysical truth, and commandment is separated from the universal work of reason. The God of Abraham, Isaac, and Jacob drops out of the horizon within which the philosopher asks what God is.

Spinoza belongs where belonging becomes uncertain. Modern Jewish philosophy cannot understand its own formation without him, yet absorbing him without qualification would erase the rupture his work created. After Spinoza, a Jew entering modern European society still faced the medieval problem of reconciling philosophy with revelation, while a second problem emerged: whether Judaism could survive in a culture that claimed universal reason, civil equality, and religious freedom as principles available to everyone.

Modernity and the Transformation of Jewish Philosophy

Moses Mendelssohn: Judaism and the Claims of Modernity

Moses Mendelssohn (1729–1786) lived this problem before he gave it philosophical form. He belonged intellectually to the German Enlightenment while remaining part of a Jewish community whose civil position was precarious.

Johann Caspar Lavater’s public challenge forced Mendelssohn into that conflict. Lavater invited him either to refute Christianity or to accept it. The challenge was couched in civil terms, but the two men stood on unequal ground. Mendelssohn lived in a state where a Jew could not publicly attack the dominant religion without risk. His response defended his Judaism and rejected the assumption that religious conviction carried an obligation to convert others. From that point forward, Judaism was inseparable from his philosophical work.

In Jerusalem (1783), Mendelssohn denies both church and state the power to compel belief. Coercion can reach conduct only, since belief cannot be produced by command. Religious communities, it follows, have no legitimate right to punish belief by excommunication or ban. He wrote this knowing that his own community held such disciplinary instruments.

On the content of Judaism he goes further still. The truths required by religion—God, providence, immortality—are available to human reason. Sinai revealed legislation, a body of commanded practices binding upon Israel; no creed inaccessible to everyone else came down with it. The political consequence was a strong defense of Jewish civil equality. Mendelssohn could argue that Jewish citizenship required no surrender of reason, while Jewish distinctiveness remained concentrated chiefly in practice.

Yet the solution left a difficulty to later generations. If the truths of Judaism belong to universal reason and the law bears the whole weight of particularity, what happens when the law itself begins to look historically contingent? Emancipation promised admission into the surrounding culture, and it also created conditions in which the distinctiveness Mendelssohn defended could be steadily translated into terms shared by everyone.

Hermann Cohen: The Return of the Particular Person

Hermann Cohen (1842–1918) spent most of his career within Marburg neo-Kantianism, a German philosophical movement that rebuilt Kant’s critical philosophy around the methods of science, ethics, and culture. His moral subject appeared under the sign of humanity; the individual entered as a participant in rational law. Late in his life, that structure proved insufficient. In Religion of Reason out of the Sources of Judaism, another person becomes philosophically real through suffering. His pain cannot be acknowledged merely as an instance of a universal category. Cohen calls this the discovery of the fellow-man. With it, ideas largely absent from his earlier system—sin, repentance, atonement, prayer—return with new force. God, once assigned a structural role in the reconciliation of morality and nature, becomes one term of a relation with the human being. Cohen still carries the weight of the older philosophical project, but the suffering person now interrupts its abstractions. Rosenzweig would make that interruption fundamental.

Franz Rosenzweig: Revelation as Address

Franz Rosenzweig (1886–1929) opens The Star of Redemption with death because death exposes what a philosophical system can conceal. A system can absorb the individual into a larger continuity: nature survives, history continues, Spirit advances. The person who dies is assigned a place inside an order whose survival is offered as consolation.

Rosenzweig refuses the exchange. The one who fears death does not experience himself as a replaceable moment in a process, and a philosophy that explains the survival of the whole has not answered his fear. God, world, and human being enter The Star as irreducible. None is dissolved into another, and no higher concept gathers them into a completed totality. Speech breaks their isolation.

Revelation, for Rosenzweig, is an address. God speaks to a human being in the second person and in the present tense. Information about God leaves the self as it was. Being addressed changes it. The soul becomes capable of answer because it has first been called.

The relation does not remain private. The person who has been addressed is turned toward another person; love moves outward into the world. Maimonides had approached revelation through what can be known and how that knowledge must be interpreted. Rosenzweig begins with a human being caught in an address before demonstration has completed its work.

Martin Buber: The Self Between I and Thou

Martin Buber (1878–1965) makes relation prior to the self. In I and Thou, the self is not fully constituted before it enters relationships, and the I that encounters an It differs from the I that addresses a Thou. I-It belongs to the ordinary world of knowledge and use. We observe and classify, measure and compare, and act upon things; without such relations, practical life would be impossible. I-Thou names a different mode, in which the other is met before being reduced to a set of properties. Buber locates this event in the between, a relation that belongs wholly to neither participant.

His examples extend beyond human beings. A tree can be studied botanically, measured, analyzed into cellular processes, and incorporated into causal explanation. It can also stand before a person in a relation not exhausted by those descriptions. Buber will neither grant the tree a humanlike consciousness nor dismiss the encounter as projection.

Every particular Thou opens toward the eternal Thou. God therefore cannot become the largest object in a universe of objects. He is encountered through relation itself, along lines of address that run through the world; withdrawal from it is not required. Here medieval negative theology finds an unexpected echo. Maimonides resisted positive predication because turning God into an object of description threatened divine unity and transcendence. Buber reaches a related prohibition from the side of relation: a God reduced to an It has ceased to be the God encountered as Thou.

His distinction nevertheless leaves much of ordinary ethical life difficult to place. Human relations rarely exist as pure encounter or pure objectification. A physician examines a body while remaining responsible to the person whose body it is; a teacher evaluates work without reducing the student to a grade; friendship itself contains habit, memory, judgment, and use. Buber acknowledges movement between the two modes, but the moral significance of this large middle ground remains underdeveloped.

Emmanuel Levinas: Responsibility Before Knowledge

Emmanuel Levinas (1906–1995) takes the problem of relation in a more severe direction. For Buber, I and Thou meet within a relation that belongs to both. Levinas distrusts the reciprocity of that structure. Ethics begins, in his account, before the participants stand on equal ground. The other person confronts me with a claim I have not chosen.

Levinas names the site of this claim the face. The term covers more than visible features or an expression waiting to be interpreted. The moment the face is completely incorporated into my knowledge, the other has become an object within my world. The face marks what exceeds the idea I possess of another person and resists being contained by it.

Its ethical meaning appears as prohibition: you shall not kill. The command comes before any completed moral theory. It arises in the exposure of another human being whose vulnerability places me under an obligation I did not negotiate.

Levinas thus reverses an order deeply embedded in Western philosophy. Ethics does not wait until ontology has determined what exists, epistemology has established what can be known, and a theory of the subject has identified the agent. Responsibility is present before such constructions are complete. The self discovers itself answerable before it discovers itself sovereign.

Other Twentieth-Century Directions: Heschel, Soloveitchik, and Fackenheim

Abraham Joshua Heschel (1907–1972) distrusted religious philosophy that begins by treating God as an object to be proved. In Man Is Not Alone and God in Search of Man, wonder, awe, and what he calls radical amazement precede conceptual mastery. The world first confronts the human being as astonishing, not as material waiting to be organized by a system. The Prophets gives this orientation an ethical and historical edge. Divine pathos (God’s concern with human conduct) makes the prophet unable to regard injustice as ordinary simply because society has learned to live with it.

Joseph B. Soloveitchik (1903–1993) keeps the intellectual priority that Rosenzweig, Buber, and Levinas loosen. In Halakhic Man, the categories of halakhah form an intellectual structure through which concrete reality is interpreted and shaped. Soloveitchik repeatedly compares this consciousness to mathematical and scientific cognition: the norm is brought to experience and becomes a measure of what the world ought to become. The Lonely Man of Faith turns to covenantal existence, where human mastery, loneliness, prayer, and community remain in tension.

The Holocaust posed a different challenge to philosophy. Emil Fackenheim (1916–2003), a German-born philosopher who survived internment under the Nazis and later taught in Canada and Israel, rejected any philosophy of history that could absorb Auschwitz as one more moment in a rational process. His phrase “the commanding voice of Auschwitz,” often summarized as a 614th commandment, names a demand to preserve Jewish existence and refuse Hitler a posthumous victory. The formulation remains contested, but it makes historical catastrophe itself a source of philosophical obligation.

Knowledge, Obligation, and Responsibility

Across much of medieval Jewish philosophy, understanding takes the first step. Questions about God, creation, providence, freedom, prophecy, and law bear directly on what the knower may say or do.

Heschel lets wonder and prophetic responsiveness precede conceptual mastery, while Rosenzweig and Buber place address and relation before completed demonstration. Levinas drives the claim further by making responsibility constitutive of the subject itself. Soloveitchik provides a counterweight: Halakhic Man approaches reality through a conceptual order formed in advance by law. Fackenheim, in turn, makes historical catastrophe itself a source of demand. Modern Jewish philosophy therefore offers no single sequence from knowledge to responsibility.

The thinker nevertheless cannot remain a spectator. Whether the claim comes through law, relation, history, or knowledge of God, thought leaves the thinker implicated in what has been understood.

What Makes Jewish Philosophy Distinctive?

No doctrine survives unchanged across the whole history of Jewish philosophy. Philo and Spinoza share no theology. Halevi and Maimonides disagree over what philosophical reason can deliver; Mendelssohn, Soloveitchik, and Levinas do not share the same conception of revelation, subjectivity, or obligation. Spinoza’s presence makes even the boundary of the tradition difficult to draw.

Continuity lies less in doctrine than in the situation from which the questions arise. Reason enters an inherited world of Scripture, covenant, practice, prayer, dispute, and communal memory. Those inheritances make claims before philosophy begins to organize them, and philosophical inquiry changes as it accepts, contests, or reinterprets what it has received.

Questions about divine unity alter the language of prayer, and arguments about freedom reshape judgment and repentance. Theories of revelation determine what authority law can claim. Interpretation decides what inherited texts require under circumstances their authors never knew, while modern accounts of the other recast the meaning of responsibility itself.

Understanding does not grant exemption.

Jewish philosophy asks what a human being can know. Again and again, the question that follows proves harder:

What must a human being do with what has been understood?

Sources and Further Reading

Primary Sources

  • Philo of Alexandria. The Works of Philo: Complete and Unabridged. Translated by C. D. Yonge. Hendrickson Publishers, 1993.
  • Saadia Gaon. The Book of Beliefs and Opinions. Translated by Samuel Rosenblatt. Yale University Press, 1948.
  • Solomon ibn Gabirol. The Font of Life (Fons Vitae). Translated by John A. Laumakis. Marquette University Press, 2014.
  • Baḥya ibn Paquda. Duties of the Heart. Translated by Daniel Haberman. Feldheim Publishers, 1996.
  • Judah Halevi. The Kuzari: In Defense of the Despised Faith. Translated by N. Daniel Korobkin. Jason Aronson, 1998.
  • Moses Maimonides. The Guide of the Perplexed. Translated by Shlomo Pines. University of Chicago Press, 1963.
  • Gersonides (Levi ben Gershom). The Wars of the Lord. Translated by Seymour Feldman. Jewish Publication Society, 1984–1999.
  • Ḥasdai Crescas. Light of the Lord (Or Hashem). Translated by Roslyn Weiss. Oxford University Press, 2018.
  • Baruch Spinoza. Theological-Political Treatise. Translated by Michael Silverthorne and Jonathan Israel. Cambridge University Press, 2007.
  • Moses Mendelssohn. Jerusalem, or On Religious Power and Judaism. Translated by Allan Arkush; introduction and commentary by Alexander Altmann. Brandeis University Press, 1983.
  • Hermann Cohen. Religion of Reason: Out of the Sources of Judaism. Translated by Simon Kaplan. Frederick Ungar, 1972.
  • Franz Rosenzweig. The Star of Redemption. Translated by Barbara E. Galli. University of Wisconsin Press, 2005.
  • Martin Buber. I and Thou. Translated by Walter Kaufmann. Charles Scribner’s Sons, 1970.
  • Abraham Joshua Heschel. Man Is Not Alone: A Philosophy of Religion. Farrar, Straus & Young, 1951; God in Search of Man: A Philosophy of Judaism. Farrar, Straus & Cudahy, 1955; The Prophets. Harper & Row, 1962.
  • Joseph B. Soloveitchik. Halakhic Man. Translated by Lawrence Kaplan. Jewish Publication Society, 1983; and “The Lonely Man of Faith,” Tradition 7, no. 2 (1965).
  • Emmanuel Levinas. Totality and Infinity. Translated by Alphonso Lingis. Duquesne University Press, 1969.
  • Emil L. Fackenheim. God’s Presence in History: Jewish Affirmations and Philosophical Reflections. New York University Press, 1970.

Studies

  • Elliot R. Wolfson. Apophasis and Envisioning the Invisible: Unveiling Veils of Infinity. Aries Book Series, vol. 42. Leiden: Brill, 2026.
  • Andrew V. Kudin. Jewish Philosophy and Kabbalah. Kudin & Sons Academic Press, 2026.
Abstract branching celestial light in deep space

About the book Jewish Philosophy and Kabbalah

Research AreaJewish Philosophy & Kabbalah