Born in Amsterdam but of Portuguese Marrano descent, Spinoza is unique in the history of modern Jewish thought. Although his work does not deal with specifically Judaic themes, he is traditionally included in this history for several reasons. First, it was through the study of Jewish philosophical texts that Spinoza was first initiated into philosophy. Second, Spinoza’s system is in part a radicalization of, or perhaps a logical corollary to, medieval Jewish doctrines, and the impact of Maimonides and of Crescas is evident. Third, a considerable portion of Spinoza’s Tractatus Theologico-Politicus deals with problems related to Judaism. He drew from Jewish religion and history, even using the Israelite commonwealth in the Tractatus as the template for his ideal state, though he was not centrally concerned with matters of Jewish theology and ritual.

The first chapters of the Tractatus show that the doctrine of prophecy is of central importance to Spinoza’s explanation of Judaism and that, in dealing with this subject, he used Maimonides’ categories, though he applied them to different people or groups of people. Maimonides held that the prophets combined intellectual perfection, which made them philosophers, with perfection of the imaginative faculty. He also referred to a category of persons, including lawyers and statesmen, endowed with a strong imagination but possessing no extraordinary intellectual gifts. Spinoza applied this category to the prophets, whom he described as possessing vivid imaginations but as not necessarily having outstanding intellectual capacities. He denied that the biblical Prophets were philosophers and used a philosophical and historical approach to the Scriptures to show that the contrary assertion is not borne out by the texts.

Spinoza also denied Maimonides’ assertion that the prophecy of Moses was essentially different from that of the other Prophets and that this was because Moses, in prophesying, had no recourse to the imaginative faculty. According to Spinoza, Moses’ prophecy was unique because he heard the voice of God in a prophetic vision—that is, in a state in which his imagination was active. In this assertion, Spinoza employed one of Maimonides’ categories of prophecy. Maimonides thought it improbable, however, that the voice of God was ever heard in prophetic vision, and he held that this category is purely hypothetical. In his classification of Moses, Spinoza was not concerned with what really happened in history; rather, he was attempting to fashion the biblical evidence according to Maimonides’ theoretical framework so that it would further his own theological and political purpose: to show that there could be a religion superior to Judaism.

This purpose made it imperative to propound in the Tractatus Theologico-Politicus a theory concerning Jesus, whom Spinoza designates as Christus. The category and the status assigned to Jesus are similar to those that Maimonides attributed to Moses. Jesus is referred to in the Tractatus as a religious teacher who makes recourse not to the imaginative faculty but to the intellect. His authority may be used to institute and strengthen the religion Spinoza called religio catholica (“universal religion”), which has little or nothing in common with any of the major manifestations of historic Christianity.

The difference between Judaism and Spinoza’s religio catholica corresponds to the difference between Moses and Jesus. After leaving Egypt, the Jews found themselves, in Spinoza’s view, in the position of people who had no allegiance to any positive law. They had, as it were, reverted to a state of nature and were faced with the need to enter into a social pact. They were also an ignorant people and very prone to superstition. Moses, a man of outstanding ability, made use of the situation and the characteristics of the people in order to make them accept a social pact and a state founded upon it that, contrary to Spinoza’s scheme for his ideal communities, were not based first and foremost upon utilitarian—that is, reasonable—consideration of the advantages of life in society over the state of nature.

According to Spinoza, the social pact concluded by the children of Israel in the desert was based upon a superstitious view of God as “King” and “Judge,” to whom the children of Israel owed their political and military successes. The children of Israel transferred political sovereignty to God rather than to the representatives of the popular will. In due course, political sovereignty was vested in Moses, God’s representative, and in his successors. In spite of Spinoza’s insistence on the superstitious foundations of the ancient Israelite state, however, his account of its regime was not wholly unsympathetic, especially regarding its ability to curb human tyranny by its doctrine of divine sovereignty. Spinoza believed that the state contained the seeds of its own destruction and that, with its extinction, the social pact devised by Moses had lapsed and all the political and religious obligations incumbent upon the Jews had become null and void.

It could be argued that, because the state conceived by Spinoza is based not on superstitious faith but on a social contract originating in rational, utilitarian considerations, it does not need to have its authority safeguarded and stabilized by means of religion. Nevertheless, Spinoza apparently believed that religion is necessary. To fulfill this need and to obviate the danger of harmful religions, he devised the religio catholica, the universal religion, which is characterized by two distinctive traits. First, its main purpose, a practical one (which is furthered by recourse to the authority of Jesus), is to impel people to act in accordance with justice and charity. Such conduct is tantamount to obedience to the laws of the state and to the orders of the magistrates, in whom sovereignty is vested. Disobedience, however, even if it springs from compassionate motives, weakens the social pact, which safeguards the welfare of all the members of the community; in consequence, its evil effects outweigh whatever good it may produce. Second, although religion, according to Spinoza, is not concerned with theoretical truth, in order to be effective the religio catholica requires dogmas, which he set forth in the Tractatus. These dogmas are formulated in terms that can be interpreted in accordance both with the philosophical conception of God that Spinoza regarded as true and with widespread superstitious ideas. It follows that if they are accepted as constituting the only creed that everybody is obliged to profess, people cannot be persecuted on account of their beliefs. Spinoza held that such persecution may lead to civil war and may thus destroy the state. Philosophers are free to engage in the pursuit of truth and to attain, if they can, the supreme goal of humanity—freedom grounded in knowledge. There can be little doubt that the furtherance of the cause of tolerance for philosophical opinions was one of Spinoza’s main objects in writing the Tractatus.

As compared with the Tractatus Theologico-Philosophicus, the Ethics, Spinoza’s major philosophical work, bears a much more ambiguous relation to Jewish medieval philosophy. In a way, Spinoza’s metaphysical system, contained in the Ethics, can be regarded as drawing aspects of medieval Aristotelianism to their logical conclusions, a step that most Jewish (and Christian and Muslim) thinkers were unwilling to take, owing to their theological conservatism.

Moses Mendelssohn

The era opened by Moses Mendelssohn (1729–86)—i.e., c. 1750 to c. 1830—is sometimes called the German period of Jewish philosophy because of the large number of works on Jewish philosophy that were written in German. The German period is also marked by the emancipation of the Jews—that is, by the abrogation of discriminatory laws directed against them—and by their partial or complete assimilation. In this time in particular, the term Jewish philosophy applied especially to works that were primarily concerned with defining Judaism and offering a justification of its existence. The second of these tasks was often conceived of as involving a confrontation with Christianity rather than with philosophy. This change from what would have been the practice in the Middle Ages seems to have resulted from the demarcation of the sphere of religion in such a way that, at least in the opinion of the philosophers, possible points of collision with philosophy no longer existed. This development was stimulated by the doctrine of Spinoza, from whom Mendelssohn and others took certain fundamental ideas concerning Judaism.

Like Spinoza, Mendelssohn held that it is not the task of Judaism to teach rational truths, though such truths may be referred to in the Bible. Contrary to what he called Athanasian Christianity—that is, the doctrine set forth in the Athanasian Creed—Judaism has no binding dogmas; it is centred on inculcating belief in certain historical events and on the observance of religious law, which includes the ceremonial commandments. Such observance is supposed to lead to happiness in this world and in the afterlife. Mendelssohn did not reject this view out of hand, as Spinoza would have done. Indeed, he seems to have been prepared to accept it, God’s mysteries being inscrutable, and the radicalism and what may be called the consistency of Spinoza being the complete antithesis of Mendelssohn’s apologetics. Non-Jews were supposed by Mendelssohn to owe allegiance to the natural moral law.

Solomon Formstecher

Whereas Mendelssohn continued the medieval tradition (at least to some extent) or adapted Spinoza’s doctrine for his own purposes, the Jewish philosophers of the first half of the 19th century generally followed the teachings of the non-Jewish philosophers of their own time. In Die Religion des Geistes (“The Religion of the Spirit”), Solomon Formstecher (1808–89) may have been influenced by F.W.J. von Schelling (1775–1854) in his conception of nature and spirit as manifestations of the divine. In Formstecher’s view, there are two types of religions that correspond to these manifestations: the religion of nature, in which God is conceived as the principle of nature or as the world soul, and the religion of the spirit, in which God is understood as an ethical being. According to the religion of the spirit, God has produced the world as his manifestation in full freedom and not, as the religion of nature tends to profess, because the world was necessary for his existence.

The religion of the spirit, which corresponds to absolute religious truth, was first manifested in the Jewish people. The religious history of the world may be understood as a process of universalization of the Jewish religion, according to Formstecher. Thus, Christianity propagated Jewish conceptions among the nations; however, it combined them with pagan ideas. The pagan element is gradually being eliminated—Protestantism, in this respect, marks considerable progress. When at long last the Jewish element in Christianity is victorious, the Jews will be right to give up their isolation. The progress that will bring about this final religious union is already under way.