But this notion of ground as ἀρχή, can be conceived still more broadly so that it encompasses both primal cause [Ur-sache] and essential ground: the first from which a being, insofar as it is this being, takes its essence, and also the first from which a being, insofar as it is actualized in such a way, begins in its actualization, in its emergence. Understood in this way, ground is the τὸ τί ἐστιν, what a thing is, its λόγος. Ratio also has this meaning of ground as essence, and in this sense causa is equated by Christian Wolff with a definite mode of ratio; this ratio is not primarily related to knowledge (or nevertheless to ontological knowledge?!).
Aristotle conjoins all three main notions of ground as ἀρχή, according to which αἴτιον [cause] is also an ἀρχή in Metaphysics Δ1 (1013 a17ff): πασῶν μὲν οὖν κοινὸν τῶν ἀρχῶν τὸ πρῶτον εἶναι ὅθεν ἢ ἔστιν ἢ γίγνεται ἢ γιγνώσκεται. "It is a common property then of all 'beginnings' to be the first thing from which something either exists or comes into being or becomes known." Ἀρχή is the ground for whatness [Wassein]; it is essence. Ἀρχή is ground for something to exist, that it is [Vorhandensein (Dass-sein)]; it is cause. Ἀρχή is ground for being true; it is argument, justifying a proposition. And if we add Dasein (human existence) and its activity, as essentially belonging with whatness, actual existence, and being true, then we have the grounds for acting: the intention (the οὗ ἕνεκα in the Nicomachean Ethics).
We can already roughly see four concepts of ground, four variations on what we can mean by "ground" and, correspondingly, four possible ways of grounding, explaining, and giving grounds: essence, cause, argument (in the sense of a "truth" ), and intention. The general-formal character of ground is " the first from which." But this neither exhausts the idea of ground nor are the four concepts of ground grasped in their interconnection with sufficient radicality and clarity, since their origin and order remain obscure.
But one thing has been attained. We have defined the range that the common formulation of the principium rationis in its generality can and usually does have. Nihil est sine ratione. Nihil, nothing—be it whatness, existence [Vorhandensein], being true, and action—nothing is as this being [Seinl without its ground. Each mode of being always has its ground. This is something new and essential: the conjunction of the idea of being as such with the idea of ground as such. Ground pertains to being.
It is easy to see that this claim itself, the principium rationis in the broadest sense, requires grounds or proof, and that this proof can obviously be given only when the essence of being as such is clarified. Inasmuch as this question is the basic question of