Tommaso d’Aquino e le dottrine non scritte di Platone

At least since the 1950s, scholars of ancient philosophy have devoted their attention to Plato's so-called "unwritten doctrines". Surprisingly enough, the same did not happen among the specialists of medieval philosophy. This is even more curious if we consider the fact that the main sources testifying the contents of those doctrines were Metaphysics and Physics by Aristotle, which became well known in the XIIIth century. The present article explores the reception of such doctrines within Thomas Aquinas’ work. Firstly it presents and discusses the main texts in Aquinas’ library on this topics: those by Aristotle (in the different translations), Averroes, Simplicius, Themistius, Boethius, Calcidius. Secondly the article examines Aquinas’ texts and commentaries in the matter of those Plato’s doctrines (Commentaries on Physica, Methaphysica, De anima, De causis): all the texts contain often open criticisms to those doctrines. Finally it is shown how such criticisms play a central role within Aquinas’ entire work (e.g. in De ente et essentia, De veritate, De potentia), being the background of his doctrine of being, of transcendentals, and of his treatises De Deo trino. Hence it arises a reconstruction of Aquinas’ thought re-considering the importance of Aristotle’s philosophy, and so going in the opposite direction of some “pan-Platonist” interpretations of his work. Presented in the Appendix are the medieval translations of a passage in Aristotle’ Metaphysics (I, 6), which is the main and at the same time the most critical source on Plato’s “unwritten doctrines”, and the corresponding Aquinas’ Commentary.