Plutarch's Platonic questions (10.2)

Besides, we must not neglect to observe, that Plato says that speech is composed of these, not by these; nor must we blame Plato for leaving out conjunctions, prepositions, and the like, any more than we should cavil at a man who should say such a medicine is composed of wax and galbanum, because fire and utensils are omitted, without which it cannot be made. For speech is not composed of these; yet by their means, and not without them, speech must be composed. As, if a man pronounce beats or is beaten, and put Socrates and Pythagoras to the same, he offers us something to conceive and understand. But if a man pronounce indeed or for or about, and no more,

none can conceive any notion of a body or matter; and unless such words as these be uttered with verbs and nouns, they are but empty noise and chattering. For neither alone nor joined one with another do they signify any thing. And join and confound together conjunctions, articles, and prepositions, supposing you would make something of them; yet you will be taken to babble, and not to speak sense. But when there is a verb in construction with a noun, the result is speech and sense. Therefore some do with good reason make only these two parts of speech; and perhaps Homer is willing to declare himself of this mind, when he says so often,

Ἐπος τ ἔφατ ἔκ τ ὀνόμαζεν.

For by ἔπος he usually means a verb, as in these verses.

Ὦ γύναι, ἤ μάλα τοῦτο ἔπος θυμαλγές ἔειπες,

and,

Χαῖρε, πάτερ, ὦ ξεῖνε, ἔπος δ εἴπερ τι λέλεκται

Δεινὸν, ἄφαρ τὸ φέροιεν ἀναρπάξασαι ἄελλαι.

[*]

For neither conjunction, article, nor preposition could be called δεινόν (terrible) or θυμαλγές (soul-grieving), but only a verb expressing a base action or a foolish passion of the mind. Therefore, when we would praise or dispraise poets or writers, we are wont to say, such a man uses Attic nouns and good verbs, or else common nouns and verbs; but none can say that Thucydides or Euripides used Attic or good or common articles.