The problems of metaphysics: the “old” metaphysics
If metaphysics now considers a wider range of problems than those studied in Aristotle's Metaphysics, those problems continue to belong to its subject-matter. “Being as such” (and existence as such, if existence is something other than being), for example, is one of the matters that belong to metaphysics on any conception of metaphysics. Thus, the following statements are all paradigmatically metaphysical: ‘Being is; not-being is not’ [Parmenides]; ‘Essence precedes existence’ [Avicenna, paraphrased]; ‘Existence in reality is greater than existence in the understanding alone’ [St Anselm, paraphrased]; ‘Existence is a perfection’ [Descartes, paraphrased]; ‘Being is a logical, not a real predicate’ [Kant, paraphrased]; ‘Being is the most barren and abstract of all categories’ [Hegel, paraphrased]; ‘Affirmation of existence is in fact nothing but denial of the number zero’ [Frege]; ‘Universals do not exist but rather subsist or have being’ [Russell, paraphrased]; ‘To be is to be the value of a bound variable’ [Quine].
(Does Berkeley's ‘Esse est percipi’ belong in this list? Not obviously, and this for reasons connected with our earlier worries about Wolff's contention that “special metaphysics” addresses the topic “being.” It is a plausible position that Berkeley's Latin slogan is not really about the being of chairs and mountains but about their natures: it means that such things, perceptible things, are essentially perceived by someone. It may be contrasted with Russell's statement about universals, which—it seems clearly to be Russell's intention to assert this—is a statement not only to the effect that universals have very different properties or natures from those of the things that “exist,” but enjoy a different mode of being. It would seem, too, that Sartre's famous epitome of existentialism, ‘Existence precedes essence’, although it is an allusion to a classical theory about existence, is not itself a statement about existence but rather about the nature of human freedom.)
It seems reasonable, moreover, to say that investigations into non-being belong to the topic “being as such” and thus belong to metaphysics. (This did not seem reasonable to Meinong, who wished to confine the subject-matter of metaphysics to “the actual” and who therefore did not regard his Theory of Objects as a metaphysical theory. According to the conception of metaphysics adopted in this article, however, his thesis [paraphrased] ‘Predication is independent of being’ is a paradigmatically metaphysical thesis.)
The two topics “the first causes of things” and “things that do not change” must also be assigned to metaphysics in the post-Medieval sense as well as in the Aristotelian/Medieval sense. The first three of Aquinas's Five Ways are thus metaphysical arguments on any conception of metaphysics. But we must not take this to imply that the thesis that there are no first causes and the thesis that there are no things that do not change are not metaphysical theses. For, in the current conception of metaphysics, the denial of a metaphysical thesis is a metaphysical thesis. No post-Medieval philosopher would say anything like this: “I study the first causes of things, and am therefore a metaphysician. My colleague Dr McZed denies that there are any first causes and is therefore not a metaphysician; she is rather, an anti-metaphysician. In her view, metaphysics is a science with a non-existent subject-matter, like astrology.” This feature of the modern conception of metaphysics is nicely illustrated by a statement of Sartre's (Sartre (1949), p. 139): “I do not think myself any less a metaphysician in denying the existence of God than Leibniz was in affirming it.” (It is instructive to compare this statement with Aristotle's thesis that first philosophy is unlike the other sciences in that it must prove the existence of its subject-matter. Cf. Loux (2006b).) And an anti-metaphysician in the modern sense is not a philosopher who denies that there are objects of the sorts that an earlier philosopher might have said formed the subject-matter of metaphysics (first causes, things that do not change, universals, substances, …), but rather a philosopher who denies the legitimacy of the question whether there are objects of those sorts.
In addition to these three topics—the nature of being; the first causes of things; things that do not change—(the latter two being understood as including attempts to show that there are no first causes or things that do not change), the topics that fall under the “old” or “Aristotelian/Medieval” conception of metaphysics, we must recognize attention to a large range of “new” or “post-Medieval” topics as no less the proper business of metaphysics than these three. (Many of these topics were well known to Aristotle and the Medievals, but they would not have classified them as belonging to protophilosophia or metaphysica.) Before we turn to these topics, however, we must consider a topic that occupies an intermediate position between them and the topic “the nature of being”. (It will be observed that many of the objects that figure in various philosophical theories that pertain to this intermediate topic are supposed to be changeless—but not first causes, since, as Aristotle noted, they are causally inactive.) We may call this topic: