Aristotle, On Gorgias 980b
“For how can someone express in words what they have seen? Or how is it possible for a thing to be clear to someone who has only heard it but has not seen it? For just as sight cannot recognize sounds, so too hearing cannot sense colors. So, the speaker speaks but not a color or a thing. How can someone communicate what is not actually in their mind in speech or in any other sign which is different from the thing itself other than through a color, if a thing is seen, or a sound if something is heard?
To start, no one speaks sound or color, but words. For this reason, it is not possible to think a color but only to see it nor a sound but only to hear it. Since we accept that we know and read words, how then does someone who hears the same thing conceptualize it?”
ὃ γὰρ εἶδε, πῶς ἄν τις, φησί, τοῦτο εἴποι λόγῳ; ἢ πῶς ἂν ἐκεῖνο δῆλον ἀκούσαντι γίγνοιτο, μὴ ἰδόντι; ὥσπερ γὰρ οὐδὲ ἡ ὄψις τοὺς φθόγγους γιγνώσκει, οὕτως οὐδὲ ἡ ἀκοὴ τὰ χρώματα ἀκούει, ἀλλὰ φθόγγους· καὶ λέγει ὁ λέγων, ἀλλ᾿ οὐ χρῶμα οὐδὲ πρᾶγμα. ὃ οὖν τις μὴ ἐννοεῖ, πῶς ἂν αὐτὸ παρ᾿ ἄλλου λόγῳ ἢ σημείῳ τινί, ἑτέρῳ τοῦ πράγματος, ἐννοήσειεν, ἀλλ᾿ ἢ ἐὰν μὲν χρῶμα, ἰδών, ἐὰν δὲ <φθόγγος, ἀκροώ> μενος; ἀρχὴν γὰρ οὐ<δεὶς> λέγει <φθόγ>γον οὐδὲ χρῶμα, ἀλλὰ λόγον· ὥστ᾿ οὐδὲ διανοεῖσθαι χρῶμα ἔστιν, ἀλλ᾿ ὁρᾶν, οὐδὲ ψόφον, ἀλλ᾿ ἀκούειν. εἰ δὲ καὶ ἐνδέχεται γιγνώσκειν τε καὶ ἀναγιγνώσκειν λόγον, ἀλλὰ πῶς ὁ ἀκούων τὸ αὐτὸ ἐννοήσει;