Being in Aristotle

“Philosophy,” Heidegger says, “is knowledge of the essence of things.”1 It searches for the causes and principles of things in order to get at the ultimate reasons that explain what, why, and how things are. With Socrates and Plato the philosophical question formally emerges in the West as the dialectical inquiry beyond, for example, virtues to virtue-ness (the Meno) or beyond pious acts to pious-ness (the Euthyphro). In general terms the philosophical question asks for the X-ness of any X. We may designate this “-ness” dimension as the essence of X, if we may use the word “essence” broadly and prescind for now from the distinction of essence/existence.

But the highest form of philosophy—what Aristotle called “first philosophy”2—asks not about the essence of particular things or regions of things (the X-ness of all Xs, the Y-ness of all Ys). It asks instead about the very “is-ness” of all-that-is, the realness that makes anything be real. It is “justified speech about the whole and the first,” or in Heidegger’s terms, about “the whole with regard to its origins.”3 It encompasses everything that exists, and inquires into it from the most universal viewpoint, that of its realness as such. In that sense, this question does not belong to any of the “partial” or “regional” sciences.4 Such sciences cut off one or another attribute of things (motion, for example, in Aristotle’s Physics) and study things under that aspect. By contrast, the question of first philosophy becomes: What is a thing, any particular thing, insofar as it is real? For Aristotle, a thing (τὸ ὄν) = something that “is” or “has being,”5 something that is “real.” But, of course, this prompts the question of what “real” means—which is the core question of all metaphysics: “What constitutes the

1. GA 45: 29.28–29 = 29.18–19: “Philosophie [ist] das Wissen vom Wesen der Dinge.” This focus on the “essence” or being [Sein] of things is what distinguishes philosophy from the sciences: “[D]as Seiende kann untersucht werden, ohne ausdrücklich nach dem Sein zu fragen,” GA 22: 8.11–12 = 6.20–21.
2. Metaphysics VI 1, 1026a30 and XI, 4, 1061b19: φιλοσοφία πρώτη. Also On the Motion of Animals 6, 700b9.
3. Respectively, Thomas Prufer, “A Protreptric,” 2; and GA 19: 212.2–3 = 146.32: “das Ganze hinsichtlich seiner Ursprünge.”
4. Metaphysics VI 1, 1003a22–23: ἐπιστήμαι ἐν μέρει λεγόμεναι.
5. GA 22: 7.14–15 = 5.36: “Es [das Seiende] ist, es hat Sein.” Heidegger’s emphasis.