Plato, Republic 1.354b
The first book of the Republic reaches an impasse. Socrates blames himself.
ἀλλ’ ὥσπερ οἱ λίχνοι τοῦ ἀεὶ παραφερομένου ἀπογεύονται ἁρπάζοντες, πρὶν τοῦ προτέρου μετρίως ἀπολαῦσαι, καὶ ἐγώ μοι δοκῶ οὕτω, πρὶν ὃ τὸ πρῶτον ἐσκοποῦμεν εὑρεῖν, τὸ δίκαιον ὅτι ποτ’ ἐστίν, ἀφέμενος ἐκείνου ὁρμῆσαι ἐπὶ τὸ σκέψασθαι περὶ αὐτοῦ εἴτε κακία ἐστὶν καὶ ἀμαθία, εἴτε σοφία καὶ ἀρετή, καὶ ἐμπεσόντος αὖ ὕστερον λόγου, ὅτι λυσιτελέστερον ἡ ἀδικία τῆς δικαιοσύνης, οὐκ ἀπεσχόμην τὸ μὴ οὐκ ἐπὶ τοῦτο ἐλθεῖν ἀπ’ ἐκείνου, ὥστε μοι νυνὶ γέγονεν ἐκ τοῦ διαλόγου μηδὲν εἰδέναι.
But just as gluttons grab at every dish that’s served and taste it before they’ve had the full enjoyment of the previous one, so I too (I think), before finding out what was the first matter for us to consider – what justice is – let go of that and rushed into considering something about it – whether it is vice and ignorance or wisdom and virtue – and again later on, when the argument fell upon us that injustice is more profitable than justice, I could not restrain myself from going away from this topic to the other one, so that what has come out of the discussion now for me is that I know nothing.