Wolff Christian (1679–1754), German philosopher and the most powerful advocate for secular rationalism in early eighteenth-century Germany. Although he was a Lutheran, his early education in Catholic Breslau made him familiar with both the Scholasticism of Aquinas and Suárez and more modern sources. His later studies at Leipzig were completed with a dissertation on the application of mathematical methods to ethics (1703), which brought him to the attention of Leibniz. He remained in correspondence with Leibniz until the latter’s death (1716), and became known as the popularizer of Leibniz’s philosophy, although his views did not derive from that source alone. Appointed to teach mathematics in Halle in 1706 (he published mathematical textbooks and compendia that dominated German universities for decades), Wolff began lecturing on philosophy as well by 1709. His rectoral address On the Practical Philosophy of the Chinese (1721) argued that revelation and even belief in God were unnecessary for arriving at sound principles of moral and political reasoning; this brought his uneasy relations with the Halle Pietists to a head, and in 1723 they secured his dismissal and indeed banishment. Wolff was immediately welcomed in Marburg, where he became a hero for freedom of thought, and did not return to Prussia until the ascension of Frederick the Great in 1740, when he resumed his post at Halle. Wolff published an immense series of texts on logic, metaphysics, ethics, politics, natural theology, and teleology (1713–24), in which he created the philosophical terminology of modern German; he then published an even more extensive series of works in Latin for the rest of his life, expanding and modifying his German works but also adding works on natural and positive law and economics (1723–55). He accepted the traditional division of logic into the doctrines of concepts, judgment, and inference, which influenced the organization of Kant’s Critique of Pure Reason (1781–87) and even Hegel’s Science of Logic (1816). In metaphysics, he included general ontology and then the special disciplines of rational cosmology, rational psychology, and rational theology (Kant replaced Wolff’s general ontology with his transcendental aesthetic and analytic, and then demolished Wolff’s special metaphysics in his transcendental dialectic).
Wolff’s metaphysics drew heavily on Leibniz, but also on Descartes and even empiricists like Locke. Methodologically, he attempted to derive the principle of sufficient reason from the logical law of identity (like the unpublished Leibniz of the 1680s rather than the published Leibniz of the 1700s); substantively, he began his German metaphysics with a reconstruction of Descartes’s cogito argument, then argued for a simple, immaterial soul, all of its faculties reducible to forms of representation and related to body by preestablished harmony. Although rejected by Crusius and then Kant, Wolff’s attempt to found philosophy on a single principle continued to influence German idealism as late as Reinhold, Fichte, and Hegel, and his example of beginning metaphysics from the unique representative power of the soul continued to influence not only later writers such as Reinhold and Fichte but also Kant’s own conception of the transcendental unity of apperception.
In spite of the academic influence of his metaphysics, Wolff’s importance for German culture lay in his rationalist rather than theological ethics. He argued that moral worth lies in the perfection of the objective essence of mankind; as the essence of a human is to be an intellect and a will (with the latter dependent on the former), which are physically embodied and dependent for their well-being on the well-being of their physical body, morality requires perfection of the intellect and will, physical body, and external conditions for the well-being of that combination. Each person is obliged to perfect all instantiations of this essence, but in practice does so most effectively in his own case; duties to oneself therefore precede duties to others and to God. Because pleasure is the sensible sign of perfection, Wolff’s perfectionism resembles contemporary utilitarianism. Since he held that human perfection can be understood by human reason independently of any revelation, Wolff joined contemporary British enlighteners such as Shaftesbury and Hutcheson in arguing that morality does not depend on divine commands, indeed the recognition of divine commands depends on an antecedent comprehension of morality (although morality does require respect for God, and thus the atheistic morality of the Chinese, even though sound as far as it went, was not complete). This was the doctrine that put Wolff’s life in danger, but it had tremendous repercussions for the remainder of his century, and certainly in Kant. See also KANT, LEIBNI. P.Gu.