Wolff is often described as a disciple or follower of Leibniz. Though there is some debate, there is some justification for which the characterization that the tendency that identifies Wolff himself to Leibniz — to some degree, both Wolff and his followers are shown to have supported some of Leibniz’s doctrines against those of the Newtonian camp. But in my opinion, Wolff is not as the rationalist and a pure follower of Leibniz as many handbooks say. He is more integral, combining many ideas from others, including Leibniz. This assertion can also can also be corresponding to his school and work life. He has broad intellectual interests, and his life work spanned almost every academic subject of his time.
It is clear and straightforward from Wolff’s own remarks how his philosophical viewpoint and that of Leibniz relate to one another. He refutes the existence of any “Leibnizian-Wolffian” philosophy as well as any intention on his part to do so. Additionally, we have to notice that when Wolff’s first started to teach and write on philosophical issues in the years 1703–1706, there was no conception of a Leibnizian philosophy. Finally, there are many other sources point out that a huge amount of instanced Wolff takes all indicate that Wolff has not followed Leibniz on various points of doctrine or disagreement with some of Leibniz’s opinions. We can take a closer look at Wolff’s ontology.
According to Wolff, “ontology, or first philosophy, is defined as the science of being in general, or insofar as it is being.” Ontology is properly called “first philosophy” because of its systematic primacy in metaphysics, and because metaphysics is first in the order of demonstration among the remaining parts of Wolff’s philosophy. That is, Wolff conceives metaphysics as the solid foundation rather than the capstone of his philosophical system, and ontology is the base of that foundation. With this in mind Wolff pays special attention to the nature and order of the principles from which his ontology begins. Two central axioms govern the whole enterprise, applying equally to the order of being and to that of knowing. They are the principle of contradiction and the principle of sufficient reason. Through an examination of familiar experiences of judging, Wolff claims to show that each of these principles involves both logical and ontological necessity. The former concerns intrinsic possibility or lack of self-contradiction, while the latter deals with extrinsic possibility or actuality. Perhaps the most striking aspect of Wolff’s treatment of these two principles is the explicit subordination of sufficient reason to contradiction. The deduction of the former from the latter exactly reverses Leibniz’s priorities and illustrates the strict systematic character of Wolff’s philosophy.
And according to Wolff, there are three basic classes of accidents: “essentialia,” “attributes,” and “modes.” For Wolff, the only substantial things to exist at any level of reality are simple substances. And simples are defined by their “essentialia” (both “compatible and prime”). That is, the essential properties that define a given simple substance are lack of mutual determination and contradiction. Wolff distinguished two “attributes”: proper attributes and common attributes, both follow from and are determined by a thing’s essentialia. Proper attributes are the properties of a thing that are determined by all the essentialia taken together, and common attributes are the properties of a thing that are determined by only some, but not all, its essentialia. Modes, in contrast, are only contingent accidents of substance. They are the properties of a thing that may or may not be present, and if actually present, they are causally the result of some contingent state of affairs. We could see Wolff’s analysis of the structure of being is different from Leibniz’s in Monadology. As for Leibniz, he only allows just one type of element in the building of the universe; his system is monistic, and the unique element has been ‘given the general name monad. When Leibniz says that monads are “simple,” he means that “which is one, has no parts and is therefore indivisible. The meaning of simple things is a huge gap for Wolff and Leibniz. Leibniz believed that any body, such as the body of an animal or man, has one dominant monad which controls the others within it. This dominant monad is often referred to as the soul. But Wolff seeks to offer a scientific account of the human soul specifically since the soul, as a simple substance for him, is understood to be part of the world. And his analysis of the human soul is often classified into his empirical and rational psychology parts.
Another interesting thing I found when I read Wolff’s German Metaphysics, he proposed statements like “we have the certainty that we and the other things exist” and ” the we and the other things are included in this primordial certainty.” When I saw this sentence, I immediately recalled Descartes’s cogito ergo sum. I feel like that, unlike Leibniz, Wolff is kind of fond of Descartes’ cogito. I would take more time to discover the influence of Descartes on Wolff in the future days.
In all, Ontology is only the first step, there’s a lot more to find out about Wolff. His cosmology, empirical and rational psychology and contemplations on theology are also worth exploring.