Epinomis is the dialogue putatively concluding the Laws. It takes up the question about the education of the higher rulers. In antiquity it was also known be the titles Philosopher or Nocturnal Council.
The scene is the same as in the: three elder men, an unnamed Athenian (who takes the lead in the discussion), Kleinias, a Cretan, and Megillus, a Spartan, discuss over the legislation of a new city, Magnesia, being founded in Crete.
The genuineness of the Epinomis has been a matter of dispute among scholars. For example, Harward, Taylor and Novotný argue for its legitimacy, while Tarán claims that it belongs to. Much of this debate depends on the way Diogenes Laertius' testimony is construed: “Some say that Philippus of Opus copied out the Laws, which were left upon waxen tablets, and it is said that he was the author of the Epinomis” (Lives of Eminent Philosophers III 37, 7-9). Ledger's stylometric analysis upholds the authenticity of the work on the ground that it resembles the Laws. Altman carries on by favouring the organic relation of the work with the rest of the platonic corpus. At any rate, If the Epinomis is indeed a genuine work, then it must have been composed, alike with the Laws, after 360 B.C. If the opposite is true, then its composition can be dated at some time after Plato's death in 347 B.C.
a) The science of the number is the most important among the sciences.
There is a science that can make its possessor genuinely wise and a virtuous citizen, that is, make him able to rule and be ruled on the basis of justice (976c7-d5). There is no doubt that this is the science of number, whose divine origin becomes apparent (976e1-4) by the fact that it is taught by heaven through the revolution of the stars (977a2-b8). Deprived of number, the human race would not be able to give an account of the things that it grasps through perception and memory (977c4-7). If lack of number entails orderliness and evil in general, it is inferable that the man who is deprived of the knowledge of number is also deprived of happiness (978a1-978b2).
"And as regards justice, goodness, beauty, and all such things, without knowledge no one who has attained true opinion will ever give a numerical account that is at all likely to persuade either himself or anyone else" (978b1-6).
b) Heavenly bodies bear divine souls
Living beings are divided in five categories, which correspond to fire, water, air, earth, and ether. The earthy ones, among which man, consist mostly of earth, whereas the heavenly ones of fire. In comparing their movement, we find that the earthy kind moves in disorder, whereas the heavenly in order (981c5-982a7). For an entity to be "alive", the combination of a body and a soul is required, so that the body can be fashioned from the soul (981a7-9, 981b5-c2); therefore, the superiority of the soul of the heavenly bodies is undisputable: "For it is a ruler, not a subject, and so ordains its decrees" (982b6-7).
"When a soul reaches the best decision in accordance with the best intelligence, the result, which is truly to its mind, is perfectly unalterable (982b7-c2), [for] this is the nature of the stars... that moving through their march and dance, the finest and most magnificent dance there is, they bring to pass what all living things need" (982e3-6).
If man can acknowledge that he, like the stars, can make the best choices, he will come to realize that a divine soul dwells inside him (982d2-e3).
c) The cognition of the unity is the highest point of the progress in knowledge
The science of numbers is the basis for the discovery of unity. First comes the understanding (through education) of the influence that odd and even numbers have on the nature of existing things; departing from there, it becomes possible to comprehend the, geometrical and stereometrical, assimilation of numbers that are dissimilar by nature; upon this knowledge, it is possible to compare sorts and kinds: that is, to discover that length, surface, and mass are predicated on the dynamic ratio 2:1 (990c5-991b4). Application of the foregoing principles in the field of astronomy yields a significant knowledge: that all things are linked through a natural bond (991d8-992a3). This explains why astronomy is the path to piety (989e190b2) and to the most important virtue (989b1-2); astronomy is also the prerogative of the few and rarefied members of the nocturnal council (989d2-4, 992c6-e1). It could be said that the knowledge drawn by the subject of astronomy vouches for the happiness in our post mortem destiny, i.e., for our ascension onto the One.
By dying, he [the possessor of this knowledge] will no longer be affected by a multitude of perceptions as he is now but will participate in a destiny of unity (992b4-8).
- Altman, W.H.F. "Why Plato wrote Epinomis: Leonardo Tarán and the Thirteenth Book of Plato’s Laws." Polis 29 (2012)
- Cooper, J. ed. Plato: Complete Works. Indianapolis, 1997.
- Harward, J. The Epinomis of Plato. Οξφόρδη, 1928.
- Ledger, G.R. Re-counting Plato: A Computer Analysis of Plato's Style. Οξφόρδη, 1989.
- Klibansky, R., Calogero, G., Lloyd, A.C., Taylor, A.E. Plato. Philebus and Epinomis. Νέα Υόρκη, 1956.
- Tarán, L. Academica: Plato, Philip of Opus, and the pseudo-Platonic Epinomis. Φιλαδέλφεια, 1975.
- Taylor, A.E. Plato and the authorship of the 'Epinomis'. Νέα Υόρκη, 1929.