§20. Rational Metaphysics (Wolff, Baumgarten)

By answering these three questions, we achieve once again a unified reflection on the basic mathematical trait of modern metaphysics. We shall see thereby what this metaphysics of pure reason claims to be; above all, we shall discern the shape the question concerning the thing has assumed in it.

Regarding I: how does this metaphysics determine its own concept, §1 runs: Metaphysica est scientia prima cognitionis humanae principia continens. “Metaphysics is the science that contains (embraces) the first principles of human cognition.” This definition of the concept gives the impression that metaphysics concerns a doctrine of cognition, hence epistemology; but previously metaphysics was held to be the science of beings as such, i.e., the being of beings. However, this metaphysics deals with beings and with being, just as [117] the older variety did; and yet the defining concept of [Baumgarten’s] metaphysics says nothing immediately about this. But the definition says just as little that the object of metaphysics is cognition as such. We must understand this definition of the concept in such a way that cognitio humana does not mean the human faculty of cognition, but that which is knowable and known by the human being from pure reason. This is being. It is necessary to present its “first principles,” i.e., the basic determinations of its essence, being. But why does the definition of the concept not simply say this, as Aristotle once did? Ἔστιν ἐπιστήμη τις ἣ θεωρεῖ τὸ ὂν ᾗ ὂν καὶ τὰ τούτῳ ὑπάρχοντα καθ᾽ αὑτό (Metaphysics Γ, 1003a21–2212)?

Why speak now about the knowable and cognition? Because now, since Descartes, the faculty of cognition, pure reason, has been established as the guiding thread by virtue of which the determinations of being, the thing, are supposed to be established in rigorous demonstration and grounding. The mathematical is the Galilean mente concipere. In the ascent toward metaphysics, this now means: it is necessary to posit a projection of the being of beings that will be authoritative for everything further knowable, and to do so out of the essence of pure rational cognition. This first takes place in the basic discipline of metaphysics, namely, ontologia, which, according to §4, is the scientia praedicatorum entis generaliorum. Kant (op. cit., pp. 115f.) translates this as the “science of the universal properties of all things.” We can see from this, first, that the concept of the thing is grasped very widely, as widely as possible. “Thing” is any being that is: God, the soul, and the world belong to [the domain of] things, too. We can see, further, that the thingness of things is determined on the basis and along the guiding thread of the principles of pure reason. We acquainted ourselves with such principles as the principle of the I, the principle of contradiction, and the principle of sufficient reason. We thereby stand directly before the answer to the second question. [118]

12 We have supplied the reference in place of Heidegger’s “zu Beginn.”

Martin Heidegger (GA 41) The Question Concerning the Thing: On Kant's Doctrine of the Transcendental Principles