272 b-d (tr. W.R.M. Lamb):
And so I, Crito, am minded to place myself in these two gentlemen's hands; for they say it would take them but a little while to make anyone else clever in just the same way.
What, Socrates! Are you not afraid, at your time of life, that you may be too old for that now?
Not at all, Crito: I have enough proof and reassurance to the contrary. These same two persons were little less than old men at the time of their taking up this science, which I desire to have, of disputation. Last year, or the year before, they were as yet without their science. The only thing I am afraid of is that I may bring the same disgrace upon our two visitors as upon Connus, son of Metrobius, the harper, who is still trying to teach me the harp; so that the boys who go to his lessons with me make fun of me and call Connus "the gaffers' master" [γεροντοδιδάσκαλον]. This makes me fear that someone may make the same reproach to the two strangers; and, for aught I know, their dread of this very thing may make them unwilling to accept me. So, Crito, just as in the other case I have persuaded some elderly men to come and have lessons with me, in this affair I am going to try and persuade another set.
Ἐγὼ μὲν οὖν, ὦ Κρίτων, ἐν νῷ ἔχω τοῖν ἀνδροῖν παραδοῦναι ἐμαυτόν· καὶ γάρ φατον ἐν ὀλίγῳ χρόνῳ ποιῆσαι ἂν καὶ ἄλλον ὁντινοῦν τὰ αὐτὰ ταῦτα δεινόν.
Τί δέ, ὦ Σώκρατες; Οὐ φοβῇ τὴν ἡλικίαν, μὴ ἤδη πρεσβύτερος ᾖς;
Ἥκιστά γε, ὦ Κρίτων· ἱκανὸν τεκμήριον ἔχω καὶ παραμύθιον τοῦ μὴ φοβεῖσθαι. Αὐτὼ γὰρ τούτω, ὡς ἔπος εἰπεῖν, γέροντε ὄντε ἠρξάσθην ταύτης τῆς σοφίας ἧς ἔγωγε ἐπιθυμῶ, τῆς ἐριστικῆς· πέρυσιν ἢ προπέρυσιν οὐδέπω ἤστην σοφώ. Ἀλλ' ἐγὼ ἓν μόνον φοβοῦμαι, μὴ αὖ ὄνειδος τοῖν ξένοιν περιάψω, ὥσπερ Κόννῳ τῷ Μητροβίου, τῷ κιθαριστῇ, ὃς ἐμὲ διδάσκει ἔτι καὶ νῦν κιθαρίζειν· ὁρῶντες οὖν οἱ παῖδες οἱ συμφοιτηταί μοι ἐμοῦ τε καταγελῶσι καὶ τὸν Κόννον καλοῦσι γεροντοδιδάσκαλον. Μὴ οὖν καὶ τοῖν ξένοιν τις ταὐτὸν τοῦτο ὀνειδίσῃ· οἱ δ' αὐτὸ τοῦτο ἴσως φοβούμενοι τάχα με οὐκ ἂν ἐθέλοιεν προσδέξασθαι. Ἐγὼ δ', ὦ Κρίτων, ἐκεῖσε μὲν ἄλλους πέπεικα συμμαθητάς μοι φοιτᾶν πρεσβύτας, ἐνταῦθα δέ γε ἑτέρους πειράσομαι πείθειν.
Sextus Empiricus, Adversus Mathematicos
Socrates, although he was already deep in old age, was not ashamed to resort to Lampo the lyre player, and to one who reproached him for this he said that it is better to be criticized for learning late than for not learning at all.
Σωκράτης καίπερ βαθυγήρως ἤδη γεγονὼς οὐκ ᾐδεῖτο πρὸς Λάμπωνα τὸν κιθαριστὴν φοιτῶν, καὶ πρὸς τὸν ἐπὶ τούτῳ ὀνειδίσαντα λέγειν ὅτι κρεῖττόν ἐστιν ὀψιμαθῆ μᾶλλον ἢ ἀμαθῆ διαβάλλεσθαι.
Seneca, Letters to Lucilius
36.4 (tr. Richard M. Gummere):
Now is the time to learn. "What? Is there any time when a man should not learn?" By no means; but just as it is creditable for every age to study, so it is not creditable for every age to be instructed. An old man learning his A B C [elementarius senex] is a disgraceful and absurd object; the young man must store up, the old man must use.
Hoc est discendi tempus. 'Quid ergo? aliquod est quo non sit discendum?' Minime; sed quemadmodum omnibus annis studere honestum est, ita non omnibus institui. Turpis et ridicula res est elementarius senex: iuveni parandum, seni utendum est.
Seneca, Letters to Lucilius
76.1-3 (tr. Richard M. Gummere):
 You have been threatening me with your enmity, if I do not keep you informed about all my daily actions. But see, now, upon what frank terms you and I live: for I shall confide even the following fact to your ears. I have been hearing the lectures of a philosopher; four days have already passed since I have been attending his school and listening to the harangue, which begins at two o'clock. "A fine time of life for that!" you say. Yes, fine indeed! Now what is more foolish than refusing to learn, simply because one has not been learning for a long time?
 "What do you mean? Must I follow the fashion set by the fops and youngsters?" But I am pretty well off if this is the only thing that discredits my declining years. Men of all ages are admitted to this class-room. You retort: "Do we grow old merely in order to tag after the youngsters?" But if I, an old man, go to the theatre, and am carried to the races, and allow no duel in the arena to be fought to a finish without my presence, shall I blush to attend a philosopher's lecture?
 You should keep learning as long as you are ignorant, - even to the end of your life, if there is anything in the proverb. And the proverb suits the present case as well as any: "As long as you live, keep learning how to live." For all that, there is also something which I can teach in that school. You ask, do you, what I can teach? That even an old man should keep learning.
 Inimicitias mihi denuntias si quicquam ex iis quae cotidie facio ignoraveris. Vide quam simpliciter tecum vivam: hoc quoque tibi committam. Philosophum audio et quidem quintum iam diem habeo ex quo in scholam eo et ab octava disputantem audio. 'Bona' inquis 'aetate.' Quidni bona? quid autem stultius est quam quia diu non didiceris non discere?
 'Quid ergo? idem faciam quod trossuli et iuvenes?' Bene mecum agitur si hoc unum senectutem meam dedecet: omnis aetatis homines haec schola admittit. 'In hoc senescamus, ut iuvenes sequamur?' In theatrum senex ibo et in circum deferar et nullum par sine me depugnabit: ad philosophum ire erubescam?
 Tamdiu discendum est quamdiu nescias; si proverbio credimus, quamdiu vivas. Nec ulli hoc rei magis convenit quam huic: tamdiu discendum est quemadmodum vivas quamdiu vivas. Ego tamen illic aliquid et doceo. Quaeris quid doceam? etiam seni esse discendum.
St. Augustine, Letters
166 (to St. Jerome, tr. Marcus Dods):
For although in addressing you I consult one much older than myself, nevertheless I also am becoming old; but I cannot think that it is at any time of life too late to learn what we need to know, because, although it is more fitting that old men should be teachers than learners, it is nevertheless more fitting for them to learn than to continue ignorant of that which they should teach to others.
Quamquam enim te multo quam ego sum aetate maiorem, tamen etiam ipse iam senex consulo: sed ad discendum quod opus est, nulla mihi aetas sera videri potest; quia etsi senes magis decet docere quam discere, magis tamen discere quam quid doceant ignorare.