The Law of Nations Treated According to the Scientific Method. Christian von Wolff

Wolff enrolled at the University of Jena as a student of divinity in 1699. It soon became clear that Wolff was more interested in mathematics and physics than theology. In his first few months at Jena he went to lectures on the theories of Johann Christoph Sturm (1635–1703), a famous mathematician and natural scientist who was teaching at the University of Altdorf near Nuremberg.⁶ Eventually, Wolff would abandon a clerical career, though he later claimed that he had hesitated for a long time, because he had wanted to obey his father’s wishes.⁷ He even preached in the Leipzig

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      Nicolai Church as late as 1706.⁸ It may be that his protestations about his plans to become a clergyman were mainly a reflection of filial piety, but whatever the reasons for his final decision, it does not seem to have been motivated by doubts about religion. Wolff remained a conventionally pious Lutheran in many respects until the very end of his life.

      In 1702 Wolff traveled to Leipzig to take his examination for a master’s degree in philosophy. He returned to Jena to work on a dissertation that would qualify him for a university teaching post in the faculty of philosophy. This dissertation was Universal Practical Philosophy, Written according to the Mathematical Method, which Wolff defended successfully at Leipzig in January 1703.⁹ It was read by the Leipzig professor of moral philosophy, Otto Mencke, who was also editor of the most important academic review journal in the Holy Roman Empire, the Leipzig Acta Eruditorum. Mencke was eager to recruit Wolff as a contributor to the journal and asked Gottfried Wilhelm Leibniz to provide an opinion on Wolff’s dissertation. Leibniz responded by generously praising Wolff’s work and sent him a congratulatory letter, thereby inaugurating their correspondence, which continued until Leibniz’s death in 1716.¹⁰

      By the time Wolff was awarded the title of lecturer (magister legens) in 1703 he was regarded as a promising young scholar. He was soon offered and accepted a position teaching mathematics at the University of Leipzig, remaining there until 1706. He then agreed to take up a position at the University of Giessen. While traveling to his new post, however, he was persuaded by the more prestigious University of Halle to join its faculty as a professor of mathematics and moved there instead.

      At first Wolff was disappointed by the state of teaching at Halle. Mathematics, he said, had been neglected, and philosophy was dominated by the doctrines of Christian Thomasius (1655–1728), whose outlook was very different from Wolff’s.¹¹ Thomasius had little interest in mathematics. He

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      was also far more skeptical than Wolff about the powers of the human intellect, arguing that wisdom was founded in the proper management of the passions, which he opposed to the subtle but vain and fruitless reasoning of “scholastic” philosophers, among whom Thomasius included his orthodox Lutheran opponents.¹² Initially, Wolff confined himself to lecturing and writing on mathematics, staying clear of philosophical subjects. But when the professor of medicine and physics, Friedrich Hoffmann, was appointed personal physician to the Prussian king and left Halle for the court at Berlin, Wolff replaced him as lecturer in natural philosophy. Wolff now had the opportunity of expanding the range of his teaching. In 1709 he published a work on the physics of air, the Aërometriae elementa.¹³ In the following years Wolff extended his teaching to other parts of philosophy, including metaphysics, ethics, and politics. In 1720 his German treatise on metaphysics appeared, Rational Thoughts concerning God, the World, and the Soul of Man, and All Things in General,¹⁴ followed by his treatise on ethics, Rational Thoughts concerning the Actions of Humans,¹⁵ and in 1721 his treatise on politics, Rational Thoughts concerning the Social Life of Humans, in Particular the Commonwealth, Communicated for the Purpose of Furthering the Happiness of Humankind.¹⁶

      The broadening of Wolff’s interests, however, brought him into conflict with his academic colleagues. Some members of the Halle theological faculty were becoming especially hostile to him. Wolff’s most prominent critic among them was the Pietist professor of theology, Joachim Lange, who would be the main person responsible for persuading Frederick

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      William I to remove Wolff from his post in 1723. Wolff later suggested (probably not without some justification) that Lange had been envious of Wolff’s popularity as a lecturer, but Lange and others, such as Johann Franz Budde at the University of Jena, also put forward genuine and well-founded philosophical criticisms of some of Wolff’s key doctrines. Their concerns centered on Wolff’s views on the foundations of moral obligation and on his notion of human free will. Wolff argued that moral conduct required no belief in a deity, a view he set out in a speech he gave on the occasion of demitting office as prorector of the university in July 1721, “On the Practical Philosophy of the Chinese.”¹⁷ According to Wolff, the ancient Chinese had had no clear idea of a deity, which, though they lacked Christian revelation, they might have derived from natural religion. The Chinese were not full-blown atheists. They believed in some kind of creator of the universe. But their knowledge of the divine attributes was so limited and confused that it was of no use for their moral theory. Even without a clear idea of a deity, however, Chinese philosophers had understood the principles of morality and been capable of acting according to them, because morality was founded on the obligation to strive toward the perfection of human nature.¹⁸ Moral action depended on a clear and distinct idea of human nature, not belief in a deity. Acting immorally was always contrary to the idea of the perfection of human nature. It was also to the disadvantage of the agent, since

      [t]he property of good is to keep us in repose and tranquillity, and that of evil is to confuse everything, turning upside down and bringing

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      about lasting chaos; the mind, which sees these possibilities in advance, turns to the attractions of good and hates evil, to the extent that it adheres to the judgement of reason. Consequently, we have a spur to seek the good that we know and to flee the evil that we recognize.¹⁹

      Lange, by contrast, subscribed to a voluntarist view of moral obligation, according to which morality was binding because it was founded on the will of God, who was the lawgiver and judge of all mankind. Certain kinds of action might be advantageous, but they were not morally good unless they were commanded by a legitimate superior, such as God, who had the right to punish all transgressions of his law. Without a clear belief in God, morality lacked any solid foundation.

      Another reason Wolff’s philosophy occasioned controversy was that he appeared to deny the existence of free will. Lange, among others, accused him of “fatalism” and of reducing human beings to automata who had no power to choose their actions but were determined to act in certain ways by factors beyond their control. Without free will it was futile to teach morality, since nobody had the power to choose one kind of action over another. Lange was referring in particular to Wolff’s work on metaphysics, Rational Thoughts concerning God, the World, and the Soul of Man, and All Things in General where Wolff had cautiously endorsed Leibniz’s theory of a preestablished harmony as the best available explanation for the relationship between mind and body. The system of a preestablished harmony was a response to the classical problem in seventeenth- and eighteenth-century philosophy of how the human mind could influence and direct actions of the physical body, even though mind and body were two different kinds of substance: the mind was generally thought to be an immaterial being without spatial dimensions; the body was material and extended. It was difficult to imagine how the former could be the cause of movement in the latter. Leibniz had concluded that mind and body did not interact with each other causally at all. Each of the two followed its own internal and necessary laws of development. They only appeared to influence each other because God had taken care that the

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      changes in both were closely coordinated, like the movements of two synchronized clocks. This idea of a preestablished harmony, however, contradicted a conventional belief in the freedom of the human will. For if mind and body each followed its own necessary laws of change, humans appeared to have no power of acting differently from the way they did. Lange, for example, believed that the human will, in order to be free, had to be “indifferent” to several possible courses of action and capable of choosing between them. Wolff