mean? We must be satisfied here with a reference to its close conjunction with the idea of being in general, with the idea of ground, (in its manifold meaning) and with the idea of preference, of the most preferred, of the ἀγαθόν (cf. more broadly, §11b, pp. 218 ff.).2
So far several things are clear: there is a common general formulation of the principle of ground; this formulation, however, conceals the multi-layered nature of the problem; this problem of ground seems, however, intrinsically related to the problem of being as such. At the same time, we maintain the problem of ground is the central problem of logic. We shall therefore try to treat the whole problem we described in three sections: I. Exposition of the dimension of the problem, II. the problem of ground itself, III. the principle of reason and the basic problems of logic as the metaphysics of truth (cf. §14).
We must bear in mind, however, that we are not trying to take up the principle of reason in any of its formulations and prove it. We are rather concerned first with shedding light on what the principle means and can mean. By clarifying what the principle means, the general nature of its being a principle must become clear; from there we can first envision what possibilities there are for proving this principle and what sort of proof it requires. It would be not only unmethodical but pointless to discuss whether the principle is immediately evident or is entailed by the nature of reason, whether it rests on experience or provides a practical postulate, before clarifying the meaning of the principle. Perhaps none of those conceptions is relevant to the essence of the principle. The principle is much too rich to be forced into these commonplace distinctions.
FIRST SECTION:
EXPOSITION OF THE DIMENSIONS OF THE PROBLEM
We want to concentrate here on the understanding of the idea of ground as it was first developed and remained prevalent, even though the whole problem has already begun to emerge. It is no accident that the idea of ground first emerges as " cause" and as
2. Cf. also the lecture course from the summer semester of 1926, Grundbegriffe der antiken Philosophie [planned as volume 22 of the Gesamtausgabe].