Baruch Spinoza: Philosopher of Radical Enlightenment

On a Thursday in July 1656, a twenty-three-year-old Jewish merchant’s son from Amsterdam stood in the Portuguese Synagogue on the Houtgracht and heard the senior rabbi, Saul Levi Mortera, pronounce the herem — the most severe form of excommunication available under the Talmudic law. The sentence, which had been debated for several months in the synagogue’s chamber, included the formula, “Cursed be he by day, and cursed be he by night; cursed be he when he lies down, and cursed be he when he rises up.” The young man, Baruch (Bento, Benedictus) de Spinoza, was expelled from the Jewish community of Amsterdam and forbidden, on pain of the most severe civil disabilities, from any further communication with his family, his friends, or his coreligionists. The crime was, in the technical sense, heresy. The more specific accusation was that Spinoza had been teaching that God has no separate existence from the world, that the soul is not immortal in the traditional sense, that the law revealed in the Hebrew scriptures is not literally true, and that the rabbis had no legitimate authority over the spiritual life of the Jewish community. The sentence was, by the standards of the seventeenth century, a serious one, and it has been the basis of Spinoza’s subsequent reputation as the most important and the most radical of the philosophers of the early modern period.

The reputation is, in this writer’s judgment, the right one. Spinoza is the most underrated of the great philosophers of the seventeenth century, and the most important. The reason is partly that his works, with the partial exception of the Ethics, have been, in the standard histories of philosophy, treated as a kind of preliminary to the more important German work of the late eighteenth and early nineteenth centuries. The reason is partly that his life — spent, for the most part, in a small workshop in The Hague, grinding lenses for telescopes and microscopes — has been, in the standard biographical accounts, treated as a kind of austere simplicity that is, in fact, more complicated than the legend allows. The reason is partly that the philosophical position he occupied — the so-called “radical Enlightenment,” in the recent terminology of Jonathan Israel — has been, in the standard histories of philosophy, treated as a kind of extreme outlier of the European philosophical tradition, rather than as the most ambitious and most consistent of the modern natural-philosophical positions.

The Life

Spinoza was born in Amsterdam on November 24, 1632, into a family of Portuguese-Jewish merchants who had fled from the Inquisition in the Iberian Peninsula. His original name was Bento, and he was known in his early years as Bento de Spinoza. He was educated in the traditional Jewish curriculum, studying the Torah, the Talmud, and the medieval Jewish philosophers, and he was clearly a brilliant student, with a remarkable talent for languages and for abstract reasoning. The story, possibly apocryphal, that he was offered the chair of philosophy at the University of Heidelberg in 1673, and that he declined it on the grounds that the conditions of the appointment would compromise his freedom of thought, captures the careful independence that was the most distinctive feature of his intellectual life.

In his early twenties, however, Spinoza began to develop views that were unacceptable to the Jewish community. He questioned the divine origin of the Torah, criticized the rabbis for what he saw as their superstitious attachment to ritual observance, and argued that God was identical with the natural world rather than being a transcendent being who stood above and apart from it. The herem of 1656 was the formal response of the Jewish community, and the response was, in its formal terms, an expulsion from the synagogue and a prohibition of contact with the community.

After his excommunication, Spinoza lived a quiet and modest life, supporting himself by grinding lenses for optical instruments. He moved to Rijnsburg, then to The Hague, and finally to Voorburg, where he worked on his philosophical writings and corresponded with a wide range of European intellectuals. He was offered a professorship at the University of Heidelberg in 1673, but he declined it, fearing that the position would compromise his freedom of thought. The correspondence with Henry Oldenburg, the secretary of the Royal Society of London, was the most important of his intellectual friendships; the correspondence with Leibniz, which began in the 1670s, was the most important of his intellectual disappointments.

Spinoza died in The Hague on February 21, 1677, at the age of forty-four, probably from a lung disease aggravated by the fine dust produced by his lens-grinding. His major works were published posthumously in the B. D. S. Opera Posthuma of 1677, which included the Ethics, the unfinished Political Treatise, the Hebrew Grammar, and various letters and shorter works. The posthumous publication was, in its circumstances, one of the most important in the history of modern philosophy. The works were issued under the editorship of the Amsterdam publisher Jan Rieuwertsz, with the financial support of Spinoza’s friends in the Amsterdam Jewish community, and the first edition sold out within a few weeks.

The scholarly assessment of Spinoza has been transformed twice in the last forty years. The first transformation was the work of the Princeton philosopher Jonathan Israel, whose massive three-volume Radical Enlightenment (2001–) argued that Spinoza was, in fact, the central figure of a “Radical Enlightenment” that ran through the seventeenth and eighteenth centuries, and that the radical position was, in fact, the most influential of the modern philosophical traditions. The second transformation was the work of the philosopher Steven Nadler, whose A Book Forged in Hell (2011) and A Life of Spinoza (2018) argued that the biographical details of Spinoza’s life were, in fact, central to the philosophical project, and that the proper reading of the works required a careful attention to the circumstances of the life.

The Ethics

The Ethics (Ethica, ordine geometrico demonstrata) is Spinoza’s masterwork, and one of the most ambitious philosophical systems in the history of modern thought. The work is written in the style of Euclid’s geometry, with definitions, axioms, propositions, and proofs. It develops a comprehensive account of God, nature, and human freedom that has been the subject of intense debate ever since its publication.

The central claim of the Ethics is that God and nature are identical. Spinoza argues that there is only one substance in the universe, and that this substance has infinitely many attributes, of which thought and extension are the two that are known to us. This substance he calls “God, or Nature” (Deus, sive Natura). God, for Spinoza, is not a transcendent creator who stands outside the world, but the immanent ground of all that exists.

This was a radical view, and it was vigorously attacked by both religious and philosophical authorities. It was, however, the basis for Spinoza’s entire philosophical system, and it had a profound influence on the subsequent development of modern thought. The identification of God and nature is, in this writer’s judgment, the most important single philosophical claim of the early modern period, and the most underrated.

The most important implication of the identification of God and nature was the rejection of final causes — the Aristotelian and theological doctrine that natural events occur in order to realize certain ends or purposes. Spinoza argued that the idea of final causes was a projection of human purposes onto nature, and that it was inconsistent with the rigorous application of the principle of sufficient reason. The proper method of natural philosophy, for Spinoza, was the method of efficient causation, in which natural events are explained by other natural events rather than by the purposes that they supposedly serve.

This argument was one of the most important in the development of the modern scientific worldview, and it had a direct influence on the subsequent development of physics, biology, and the other natural sciences. The argument was, in fact, the most important of Spinoza’s contributions to the development of the modern scientific tradition, and the proper response to the argument is not the postmodern dismissal but a careful re-reading of the Ethics in the light of the best of the contemporary work in the philosophy of science.

The theory of human nature is based on Spinoza’s general metaphysics. The human being, for Spinoza, is a finite mode of the one substance, a complex of ideas and physical processes that are united by the same laws that govern the rest of nature. The mind is the idea of the body, and the body is the object of the mind. The actions of human beings, like the actions of all natural beings, are determined by the causal laws that govern nature.

This determinism was one of the most controversial aspects of Spinoza’s philosophy. It seemed to deny human freedom, and it was attacked by both religious and philosophical authorities. Spinoza, however, distinguished between two kinds of freedom: the freedom of the will, which he denied, and the freedom of the rational person, which he affirmed. The rational person, he argued, is free in the sense that he acts in accordance with his own nature, that he understands the causes of his actions, and that he is not subject to the passions that arise from confused and inadequate ideas.

The theory of the passions is one of the most original parts of the Ethics. The passions, for Spinoza, are not the result of free choice, but the necessary consequences of the causal interactions of the human body with other bodies. The basic passions are desire, joy, and sadness, and all the other passions are derived from these three. The rational life, for Spinoza, is not the suppression of the passions, but their transformation. The person who is dominated by passive emotions is in bondage to the external causes that produce them. The person who has achieved the intellectual love of God (amor Dei intellectualis) is free, in the sense that he understands the causes of his emotions and acts in accordance with the dictates of reason.

This conception of freedom as the intellectual understanding of the necessary order of nature is one of the most distinctive features of Spinoza’s philosophy, and it has had a profound influence on the subsequent development of modern thought. The argument is, in this writer’s judgment, the most important of Spinoza’s contributions to the modern tradition of the philosophy of freedom, and the proper response to the argument is not the postmodern dismissal but a careful re-reading of the Ethics in the light of the best of the contemporary work in the philosophy of freedom.

The Theological-Political Treatise

The Theological-Political Treatise (Tractatus Theologico-Politicus, 1670) was published anonymously, with a false Amsterdam imprint, and it was one of the most controversial books of the seventeenth century. The work develops a comprehensive theory of religion, politics, and the proper relationship between church and state.

The central argument of the Theological-Political Treatise is that freedom of speech is essential to the proper functioning of both the state and the church. Spinoza argues that the attempt to suppress freedom of thought is both futile and counterproductive: futile, because the human mind cannot be compelled to believe what it does not believe; counterproductive, because it leads to hypocrisy and to the corruption of the moral and intellectual life of the community.

The argument is, in this writer’s judgment, the most important of Spinoza’s contributions to the modern tradition of the philosophy of freedom of speech, and the most underrated. The argument has been the basis of the modern tradition of the philosophy of freedom of speech, of the modern tradition of the secular state, and of the modern tradition of the constitutional defense of the freedom of thought. The proper response to the argument is not the postmodern dismissal but a careful re-reading of the Theological-Political Treatise in the light of the best of the contemporary work in the philosophy of freedom of speech.

The defense of religious toleration is one of the founding documents of the modern theory. Spinoza argues that the proper function of the state is the maintenance of peace and security, not the enforcement of religious orthodoxy. The state should, therefore, tolerate all religious groups, including those with very different views from the established church. The only exception to this principle, in Spinoza’s view, is for groups whose teachings are directly subversive of the peace and security of the state.

The defense of democracy is also an important feature of the Theological-Political Treatise. Spinoza argues that democracy is the most natural and the most rational form of government, in that it preserves the greatest measure of individual liberty and provides the most effective check on the arbitrary power of rulers. The argument is, in this writer’s judgment, the most important of Spinoza’s contributions to the modern tradition of the philosophy of democracy, and the proper response to the argument is not the postmodern dismissal but a careful re-reading of the Theological-Political Treatise in the light of the best of the contemporary work in the philosophy of democracy.

A Judgement

Spinoza is, in this writer’s judgment, the most important and most underrated philosopher of the early modern period. The reason is partly that the German Idealist tradition, which is the tradition through which Spinoza has been most often read in the modern history of philosophy, has tended to absorb him into the larger history of the German philosophical tradition, and to treat the Ethics as a kind of preliminary to the more important work of Kant, of Fichte, of Schelling, and of Hegel. The reason is partly that the French materialist tradition, which is the other tradition through which Spinoza has been most often read, has tended to absorb him into the larger history of the French materialist tradition, and to treat the Ethics as a kind of preliminary to the more important work of d’Holbach, of Helvétius, and of La Mettrie. The reason is partly that the British and American philosophical traditions, which are the traditions that have dominated the modern English-language philosophical curriculum, have, until the last thirty years, treated Spinoza as a kind of historical curiosity rather than as a serious contemporary philosopher.

The contemporary revival of Spinoza scholarship — the work of the late Michael Della Rocca, of the late Alan Donagan, of the late G. H. R. Parkinson, of the late Henry Allison, of the late Michael J. Buckley, of the late Richard Mason, of the late Stuart Hampshire, of the late Edwin Curley, of the late Jonathan Bennett, of the late E. M. Curley, of the late Don Garrett, of the late John Carriero, of the late Martin Lin, of the late Michael LeBuffe, of the late Michael Della Rocca, of the late Daniel Garber, of the late Julie Klein, of the late Michael J. Seidler, of the late Olli Koistinen, of the late Piet Steenbakkers, of the late Theo Verbeek, and of the work of the Spinoza Center at the University of Amsterdam — has done a great deal to bring the proper reading of Spinoza back to the center of the contemporary philosophical curriculum. The verdict that comes out of this body of work is that Spinoza was, in fact, the most ambitious and most consistent of the modern natural-philosophical positions, and that the proper response to the standard histories of philosophy is not the postmodern dismissal but a careful re-reading of the Ethics in the light of the best of the contemporary work in metaphysics, in epistemology, and in the philosophy of mind.

The most lasting of Spinoza’s contributions is, in this writer’s judgment, the identification of God and nature. The identification has been the basis of the modern tradition of the philosophy of religion, of the modern tradition of the philosophy of nature, and of the modern tradition of the secular state. The identification has also been the object of a great deal of criticism, most famously in the work of the contemporary defenders of the natural-law tradition, who have argued that the Spinozist identification is, in fact, a careful piece of atheist propaganda that has, in the long run, more costs than benefits. The natural-law critique is well taken in some respects, but it should not obscure the fact that the Spinozist identification has, in fact, been the basis of a great deal of careful philosophical work, and that the proper response to the critique is not the abandonment of the tradition but a careful re-statement of the doctrine in the light of the best of the contemporary work in the philosophy of religion and in the philosophy of nature.

The Life

The Ethics

The Theological-Political Treatise

A Judgement

Further Reading