These sayings [‘Apophthegmata’] are drawn from the Gnomologium Vaticanum.

470: “Socrates, when asked what is sweetest in life, said “education, virtue, and the investigation of the unknown”

Σωκράτης ὁ φιλόσοφος ἐρωτηθεὶς τί ἥδιστον ἐν τῷ βίῳ εἶπε· „παιδεία καὶ ἀρετὴ καὶ ἱστορία τῶν ἀγνοουμένων”.

24: “Aristippos used to say the he took money from students not in order to straighten their lives but how so they might learn to spend their money on fine things.”

῾Ο αὐτὸς παρὰ τῶν μαθητῶν λαμβάνειν ἔφασκε μισθόν, οὐχ ὅπως τὸν βίον ἐπανορθώσῃ, ἀλλ’ ὅπως ἐκεῖνοι μάθωσιν εἰς τὰ καλὰ δαπανᾶν.

50: “Aristotle said that education is a decoration for the lucky but a refuge for the unfortunate.”

῾Ο αὐτὸς ἔφη τὴν παιδείαν εὐτυχοῦσι μὲν εἶναι όσμον, ἀτυχοῦσι δὲ καταφύγιον.

87: “When he was asked whom he loved more, Phillip or Aristotle, Alexander said “both the same—for the first gave me the gift of life and the second taught me to live well.”

῾Ο αὐτὸς ἐρωτηθεὶς τίνα μᾶλλον ἀγαπᾷ, Φίλιππον ἢ ᾿Αριστοτέλην, εἶπεν· „ὁμοίως ἀμφοτέρους· ὁ μὲν γάρ μοι τὸ ζῆν ἐχαρίσατο, ὁ δὲ τὸ καλῶς ζῆν ἐπαίδευσεν.”

164: “Glukôn the philosopher called education a sacred refuge.”

Γλύκων ὁ φιλόσοφος τὴν παιδείαν ἔλεγεν ἱερὸν ἄσυλον εἶναι.

259: “When Demetrios [of Phalerus] was asked what was the noblest of animals he said “A human adorned by education.”

῾Ο αὐτὸς ἐρωτηθεὶς τί τῶν ζώων κάλλιστόν ἐστιν εἶπεν· „ἄνθρωπος παιδείᾳ κεκοσμημένος”.

302: “[Zeno the Stoic] used to say that education was sufficient for happiness”

῾Ο αὐτὸς ἔφη τὴν παιδείαν πρὸς εὐδαιμονίαν αὐτάρκη.

314: “Heraclitus used to say that learning is a second sun for the educated”

῾Ηράκλειτος τὴν παιδείαν ἕτερον ἥλιον εἶναι τοῖς πεπαιδευμένοις ἔλεγεν.

439: [Plato] used to say that someone being educated needs three things: ability, practice and time.”

῾Ο αὐτὸς ἔλεγεν ὅτι ὁ παιδευόμενος τριῶν τούτων χρῄζει· φύσεως, μελέτης, χρόνου.

469: “[Protagoras] used to say “knowing a lot helps a lot and hurts a lot.”

῾Ο αὐτὸς ἔφη· „πολυμαθίη κάρτα μὲν ὠφελέει, κάρτα δὲ βλάπτει”.

Other passages

Euripides, Iphigenia at Aulis 559-567

“Men have different natures;
They have different ways. But acting rightly
Always stands out.
The preparation of education
points the way to virtue.
For it is a mark of wisdom to feel shame
and it brings the transformative grace
of seeing through its judgment
what is right; it is reputation that grants
an ageless glory to your life.”

διάφοροι δὲ φύσεις βροτῶν,
διάφοροι δὲ τρόποι· τὸ δ’ ὀρ-
θῶς ἐσθλὸν σαφὲς αἰεί·
τροφαί θ’ αἱ παιδευόμεναι
μέγα φέρουσ’ ἐς τὰν ἀρετάν·
τό τε γὰρ αἰδεῖσθαι σοφία,
†τάν τ’ ἐξαλλάσσουσαν ἔχει
χάριν ὑπὸ γνώμας ἐσορᾶν†
τὸ δέον, ἔνθα δόξα φέρει
κλέος ἀγήρατον βιοτᾶι.

Stobaeus 2.31 88

“Diogenes used to say that educating children was similar to potters’ sculpting because they take clay that is tender and shape it and decorate it how they wish.  But once it has been fired, it can’t be shaped any longer.  This is the way it is for those who were not educated when they were children: once they are grown, they have been hardened to change.”

Διογένης ἔλεγε τὴν τῶν παίδων ἀγωγὴν ἐοικέναι τοῖς τῶν κεραμέων πλάσμασιν· ὡς γὰρ ἐκεῖνοι ἁπαλὸν μὲν τὸν πηλὸν ὄντα ὅπως θέλουσι σχηματίζουσι καὶ ῥυθμίζουσιν, ὀπτηθέντα δὲ οὐκέτι δύνανται πλάσσειν, οὕτω καὶ τοὺς ἐν νεότητι μὴ διὰ πόνων παιδαγωγηθέντας, τελείους γενομένους ἀμεταπλάστους γίνεσθαι.

Antisthenes, fr. 38

“The examination of words is the beginning of education.”

ἀρχὴ παιδεύσεως ἡ τῶν ὀνομάτων ἐπίσκεψις

Alcman, fr. 125

“Trying is the first step of learning”

πῆρά τοι μαθήσιος ἀρχά

Dionysus Thrax, On the Art of Grammar (2nd to 1^st Centuries BCE; go here for a nice translation of the remaining works)

“The art of grammar is the experience-derived knowledge of how things are said, for the most part, by poets and prose authors. It has six components. First, reading out loud and by meter; second, interpretation according to customary compositional practice; third, a helpful translation of words and their meanings; fourth, an investigation of etymology; fifth, a categorization of morphologies; and sixth—which is the most beautiful portion of the art–the critical judgment of the compositions.”

Γραμματική ἐϲτιν ἐμπειρία τῶν παρὰ ποιηταῖϲ τε καὶ ϲυγγραφεῦϲιν ὡϲ ἐπὶ τὸ πολὺ λεγομένων.   Μέρη δὲ αὐτῆϲ ἐϲτιν ἕξ· πρῶτον ἀνάγνωϲιϲ ἐντριβὴϲ κατὰ προϲῳδίαν, δεύτερον ἐξήγηϲιϲ κατὰ τοὺϲ ἐνυπάρχονταϲ ποιητικοὺϲ τρόπουϲ,  τρίτον γλωϲϲῶν τε καὶ ἱϲτοριῶν πρόχειροϲ ἀπόδοϲιϲ, τέταρτον ἐτυμολογίαϲ εὕρεϲιϲ, πέμπτον ἀναλογίαϲ ἐκλογιϲμόϲ, ἕκτον κρίϲιϲ ποιημάτων, ὃ δὴ κάλλιϲτόν ἐϲτι πάντων τῶν ἐν τῇ τέχνῃ.

Sophocles, fr. 843

“I learn what can be taught; I seek what
can be found; and I ask the gods what must be prayed for.”

τὰ μὲν διδακτὰ μανθάνω, τὰ δ’ εὑρετὰ
ζητῶ, τὰ δ’ εὐκτὰ παρὰ θεῶν ᾐτησάμην

Phocylides

“It is right to teach noble things to one who is still a child”

χρὴ παῖδ᾿ ἔτ᾿ ἐόντα / καλὰ διδάσκειν ἔργα

 

Aristotle, According to Diogenes Laertius, Vitae Philosophorum 5.21

“He said that the root of education is bitter but the fruit is sweet.”

Τῆς παιδείας ἔφη τὰς μὲν ῥίζας εἶναι πικράς, τὸν δὲ καρπὸν γλυκύν.

“He used to say that three things are needed for education: innate ability, study, and practice”

τριῶν ἔφη δεῖν παιδείᾳ, φύσεως, μαθήσεως, ἀσκήσεως.

When asked what the difference was between those who were educated and those who were not, Aristotle said “as great as between the living and the dead.” He used to say that education was an ornament in good times and a refuge in bad.

ἐρωτηθεὶς τίνι διαφέρουσιν οἱ πεπαιδευμένοι τῶν ἀπαιδεύτων, “ὅσῳ,” εἶπεν, “οἱ ζῶντες τῶν τεθνεώτωντὴν παιδείαν ἔλεγεν ἐν μὲν ταῖς εὐτυχίαις εἶναι κόσμον, ἐν δὲ ταῖς ἀτυχίαις καταφυγήν

Heraclitus, fr. 40

“Knowing much doesn’t teach you how to think.”

πολυμαθίη νόον ἔχειν οὐ διδάσκει.