Plato's Sophist [211-212]

Φύσις signifies precisely a being which has the ἀρχή of its Being in itself rather than, as is the case with ποίησις (here is the opposition) by means of human knowledge and production. More precisely, Aristotle applies this expression φύσις τις to the ὄν, to the characters of Being, in order to indicate that they themselves are present as determinations by means of themselves. Furthermore, he points out at a28ff., the ancients, when they inquired into the στοιχεῖα, the elements of beings, offered various answers: water, air, earth, etc. That is, their inquiries did not properly investigate a determinate region of beings, and the ancients did not intend to recount how beings look as to content. On the contrary, they were actually guided by an interest in determining the Being of beings. It is just that the ancients were not yet on the level of a consideration which understands that beings as beings cannot be elucidated on the basis of a determinate region of beings but only by means of Being itself. With this reference to an admittedly imperfect way of questioning the Being of beings, Aristotle desires at the same time, as he always does, to bring his idea of first philosophy and of the science of Being into continuity with the previous tradition of research.

Now this science is one that falls in a preeminent way within the tasks of the philosopher. περὶ τούτων (chapter 2, 1004a32f.), i.e., about the determinations of beings, καὶ τῆς οὐσίας, and above all about οὐσία, it is necessary λόγον ἔχειν, i.e.—if we do not translate this directly—it is necessary to have beings as exhibited in speech. Thus it is necessary to exhibit the Being of beings. καὶ ἔστι τοῦ φιλοσόφου περὶ πάντων δύνασθαι θεωρεῖν (1004a34f.). "And it is the peculiar right and task of the philosopher δύνασθαι, to bear, as the one who knows, the possibility of initiating an investigation περὶ πάντων, about everything." But we realize from what preceded, from our interpretation of the second chapter of Metaphysics I,2 that περὶ πάντων does not refer to everything in the sense of a sum total, but to the whole with regard to its origins.

Aristotle develops further this idea of the original science of Being by pointing out that every being which is what it is is a ἕν. Unity—that every something is one—likewise devolves upon this science. That is to say, the ἕν is included in the thematic field of this original science of Being. In addition, further questions belong to this field, such as εἰ ἓν ἑνὶ ἐναντίον (1004b3), "whether there is something which as one is opposed to another one." Ἐναντίον means "over and against," in a certain sense lying in view of the other. And further: τί ἐστι τὸ ἐναντίον (b3f.), what properly is this "against" of the "over and against," and ποσαχῶς λέγεται, in how many ways can one speak of what is over and against ("contrary" is no longer appropriate in this context).

2. Cf. p. 65ff.