(c) Plato's Division, or the articulation of a relatively indeterminate and generic concept into species and sub-species with resultant determinate judgments, presumes of course the doctrine of the interpenetration of ideas laid down in the _Sophistes_ as the basis of predication, but its use precedes the positive development of that formula, though not, save very vaguely, the exhibition of it, negatively, in the antinomies of the one and the many in the _Parmenides_. It is its use, however, not the theory of it, that precedes. The latter is expounded in the _Politicus_ (260 sqq.) and _Philebus_ (16c sqq.). The ideal is progressively to determine a universe of discourse till true _infimae species_ are reached, when no further distinction in the determinate many is possible, though there is still the numerical difference of the indefinite plurality of particulars. The process is to take as far as possible the form of a continuous disjunction of contraries. We must bisect as far as may be, but the division is after all to be into limbs, not parts. The later examples of the _Politicus_ show that the permission of three or more co-ordinate species is not nugatory, and that the precept of dichotomy is merely in order to secure as little of a _saltus_ as possible; to avoid e.g. the division of the animal world into men and brutes. It is the middle range of the [Greek: mesa] of _Philebus_ 17a that appeals to Bacon, not only this but their mediating quality that appeals to Aristotle. The _media axiomata_ of the one and the _middle term_ of the other lie in the phrase. Plato's division is nevertheless neither syllogism nor _exclusiva_. It is not syllogism because it is based on the disjunctive, not on the hypothetical relation, and so extends horizontally where syllogism strikes vertically downward. Again it is not syllogism because it is necessarily and finally dialectical. It brings in the choice of an interlocutor at each stage, and so depends on a concession for what it should prove.[12] Nor is it Bacon's method of exclusions, which escapes the imputation of being dialectical, if not that of being unduly cumbrous, in virtue of the cogency of the negative instance. The Platonic division was, however, offered as the scientific method of the school. A fragment of the comic poet Epicrates gives a picture of it at work.[13] And the movement of disjunction as truly has a place in the scientific specification of a concept in all its differences as the linking of lower to higher in syllogism. The two are complementary, and the reinstatement of the disjunctive judgment to the more honourable rôle in inference has been made by so notable a modern logician as Lotze. Combination.