Abstract

Limits of the Conversation about Forms. Types of Knowledge and Necessity of Forms in Plato's "Parmenides". - Forms (ideas) are among the things that Plato is serious about. But about these things he says in his "Seventh Letter": "There neither is nor ever will be a treatise of mine on the subject." (341c, transl. J. Harward). Plato's statement suggests the question, why one does not and never can do justice to the Platonic forms by means of a written text about the forms. Another big question of Plato research is whether the conversations documented in the Platonic dialogues are also affected by this verdict. This paper aims to provide, as far as possible, newly substantiated answers to these two questions. To this end, the systematic limits of the discussion about forms, which are particularly evident in Plato's dialogue "Parmenides", are examined in eight steps: First, two types of knowledge are presented that play an important systematic role in Plato's philosophy with regard to the limits of conversation: knowledge-how (practical knowledge) and knowledge-that (propositional knowledge) (I). Then the Socratic model of these two types of knowledge is interpreted, which is drafted in the tenth book of the "Republic". This model uses the example of bridle, bridlemaker and rider to explain the primacy of practical knowledge and the limits of propositional knowledge (II). Subsequently, it will be shown how the dialogues "Republic" and "Parmenides" are connected with each other in content and form (III). The gradation of the two types of knowledge, which is indicated by the motifs of the bridle and the horse on the image level of the "Parmenides", proves to be the structure that systematically underlies the structure of the entire dialogue (IV). It also makes clear why the conversation about the forms in the first part of the "Parmenides" has to fail (V). The assumption that the two parts of the "Parmenides" express two different types of knowledge in dealing with forms is supported by the results of a logical analysis of the last defence of the acceptance of forms (135b-c). This analysis shows why, for reasons of principle, it is impossible to speak adequately about forms (VI). Forms have the function of being presuppositions of 'talking about something'. Thus forms are always presupposed in conversation when one talks about them, and thus elude appropriate discussion in conversation (VII). That this is not only a methodical insight of the Platonic Parmenides, but can also be attributed to Plato himself, is demonstrated by the concluding reinterpretation of the central sentence of the critique of writing in Plato's "Seventh Letter". It will become apparent that, contrary to the now widespread view of the representatives of the Tübingen school, philosophical and also good philological reasons speak for the fact that Plato related his criticism only to the communicability of forms through treatises, i.e. tract-like writings (VIII).