At the centre of the monograph (1984, first edition) lies a detailed interpretation and critique of the idea of the Good in the Republic. The main thesis of the interpretation runs as follows: The idea of the Good functions as a third item between thinking and being. The main purpose of the monograph is to introduce the systematic problem of the third item via the historical problem of the idea of the Good. The second, enlarged edition (1989) gives a new (...) reconstruction of an "exasperatingly difficult but ever fascinating topic" (H. Cherniss), that is, of the platonic theory of the ideal numbers and the two principles that were contained in the “so-called unwritten doctrines” (Aristotle). The final chapter gives new information on the reception of Plato's idea of the Good in P. Natorp and M. Heidegger. It also includes an updated bibliography. The third edition (2015) is a reprint of the second edition of 1989. Further remarks and an updated bibliography to 2005 are to be found in: - Ferber, Rafael (2005). Ist die Idee des Guten nicht transzendent oder ist sie es doch? Nochmals Platons ΕΠΕΚΕΙΝΑ ΤΗΣ ΟΥΣΙΑΣ. In: Barbaric Damir: Platon über das Gute und die Gerechtigkeit / Plato on Goodness and Justice / Platone sul Bene e sulla Giustizia. Würzburg, 149-174. - Ferber, Rafael / Damschen, Gregor (2015). Is the Idea of the Good Beyond Being? Plato's "epekeinea tês ousias" Revisted (Republic, 6, 509b8-10). In: Nails, Debra; Harold, Tarrant; Kajava, Mika; Salmenkivi, Eero. Second Sailing: Alternative Perspectives on Plato. Espoo, 197-203. (shrink)

We critically reconsider an old hypothesis of the role of the dekad in Pythagorean philosophy. Unlike Zhmud, we claim that: 1) the dekad did play a role in Philolaus’ astronomical system, and 2) Aristotle did not project Plato’s theory of the ten eidetic numbers onto the Pythagoreans. We claim that the dekad, as the τέλειος ἀριθμός, should be understood in Philolaus’ philosophy as completeness and the basis of counting in Greek – as in most other languages – in a decimal (...) system. Additionally, we argue that the number ten is not even a candidate for the τέλειος ἀριθμός in Plato’s philosophy. As a final result of our discussion, we compare and contrast Philolaus’, Plato’s, and Speusippus’ accounts of completeness in relation to numbers. (shrink)