ἀγεωμέτρητος μηδεὶς εἰσίτω / Ageōmétrētos mēdeìs eisítō.

Αncient Greek phrases

The School of Athens. Fresco by Raphael (1510–1511)

ἀγεωμέτρητος μηδεὶς εἰσίτω.

Ageōmétrētos mēdeìs eisítō.

"Let no one untrained in geometry enter."

Motto over the entrance to Plato's Academy (quoted in Elias' commentary on Aristotle's Categories (Eliae in Porphyrii Isagogen et Aristotelis categorias commentaria, CAG XVIII.1, Berlin 1900, p. 118.13–19))

Henri-Dominique Saffrey, "Ἀγεωμέτρητος μηδεὶς εἰσίτω. Une inscription légendaire." In: Revue des études grecques 81 (1968, pp. 67–87), p. 81.