Plato, Meno 72b

περὶ τὰ σμήνη, εἴ μου ἐρομένου μελίττης περὶ οὐσίας ὅτι ποτʼ ἐστίν, πολλὰς καὶ παντοδαπὰς ἔλεγες αὐτὰς εἶναι, τί ἂν ἀπεκρίνω μοι, εἴ σε ἠρόμην· ἆρα τούτῳ φῂς πολλὰς καὶ παντοδαπὰς εἶναι καὶ διαφερούσας ἀλλήλων, τῷ μελίττας εἶναι; ἢ τούτῳ μὲν οὐδὲν διαφέρουσιν, ἄλλῳ δέ τῳ, οἷον ἢ κάλλει ἢ μεγέθει ἢ ἄλλῳ τῳ τῶν τοιούτων; εἰπέ, τί ἂν ἀπεκρίνω οὕτως ἐρωτηθείς; τοῦτʼ ἔγωγε, ὅτι οὐδὲν διαφέρουσιν, ᾗ μέλιτται εἰσίν, ἡ ἑτέρα τῆς ἑτέρας.

suppose I should ask you what is the real nature of the bee, and you replied that there are many different kinds of bees, and I rejoined: Do you say it is by being bees that they are of many and various kinds and differ from each other, or does their difference lie not in that, but in something else—for example, in their beauty or size or some other quality? Tell me, what would be your answer to this question? Why, this—that they do not differ, as bees, the one from the other.