「分割法」考案 : プラトン後期対話篇への視点

Abstract

It is in the Phaedrus that Plato for the first time formally introduces the method of division (and its reverse procedure, collection), which from then onwards constructs frames of his later dialogues such as the Sophista, Politicus and Philebus. While the method is explicitly identified with dialectic or philosophy, most interpreters have entertained that the "dialectic" is not same as in the Respublica, Plato's masterpiece written before the Phdr. Their alleged reason was : the method of the Phdr. is but a classification per genera et species and then does not aim at the cognition of the Form of the Good conceived as the source of all being and all knowledge. In this paper, however, I attempt to demarcate the characters of Platonic division and locate it in the context of the theory of Forms (Paradigmatism) . First, I conclude from the observation of the "angler" division (Sph. 219a-221c) that the role of collection must be supposed in the following steps, a) the original response to the Socratic "What is X ?" question, that collects X's particular instances into one form, b) the enlargement by which many similars to that form make up together one domain, c) the reverse operation of division in the sense that to separate is at the same time to gather. As for division, its performance assumes three phases, 1) as an enunciational apparatus, 2) as a selection, 3) as a heuristic projection or metaphor. 1) In virtue of the revelation of differences among similarities the division proceeds paring the parts from which the definiendum X is absent, and ultimately sights the property of X. It is, therefore, an apparatus by which the original collection a) is articulated and enunciated. 2) This is indicated in such passages as the Sph. 226d and Pit. 303d. For their ground, these divisions require the knowledge of the just or good, which is the main motive of Plato's Pardigmatism. The puzzle of "sophistry of noble family" (Sph. 226b-231b), I esteem, can be resolved in this place. 3) In the Phdr. and Plt. as well as in Plato's earlier writings, the methodological distinction is drawn between D-things and S-things (as C. Strang calls them) . The division of S-thing (e. g. angler, weaving) admits of being projected into the range of D-thing (e.g. sophist, statesman) and aids their cognition. Here the same assumptions as Plato's Paradigmatism will be detected through the scrutiny of the Plt. 285d-286a. Finally, in order to reinforce this argument, I make comments on the so-called "criticism" of the theory of Forms in the Parmenides 130b-135c