Abstract
The article tries to prove that the famous formula "epekeina tês ousias" (R.509b8) has to be understood in the sense of being beyond being and not only in the sense of being beyond essence. We hereby make three points: first, since pure textual exegesis of 509b8–10 seems to lead to endless controversy, a formal proof for the metaontological interpretation could be helpful to settle the issue; we try to give such a proof. Second, we offer a corollary of the formal proof, showing that self-predication of the form of the Good, or of any form, is not possible, that is: no form of F has the form of F. Third, we apply Spinoza’s distinction between an “ens imaginarium” and a “chimaera” to Plato’s Idea of the Good.