Demetrius, On Style 11
“Aristotle defines the period in this way: The period is a statement which has beginning and an end. He has defined it very well and properly. For, saying the word “period” emphasizes that it begins in a place and ends in a place and is moving toward some goal, like runners once they take off, since the end of the race is already clear to them from the beginning.
This is where the name “period” comes from, an analogy from the circular paths which wind around to an end. Generally speaking, a period is nothing other than a certain kind of composition of words. If you take away its arrangement and circular nature, the subjects remain the same but it is no longer a period.”
(11) Ἀριστοτέλης δὲ ὁρίζεται τὴν περίοδον οὕτως, “περίοδός ἐστι λέξις ἀρχὴν ἔχουσα καὶ τελευτήν,” μάλα καλῶς καὶ πρεπόντως ὁρισάμενος· εὐθὺς γὰρ ὁ τὴν περίοδον λέγων ἐμφαίνει, ὅτι ἦρκταί ποθεν καὶ ἀποτελευτήσει ποι καὶ ἐπείγεται εἴς τι τέλος, ὥσπερ οἱ δρομεῖς ἀφεθέντες· καὶ γὰρ ἐκείνων συνεμφαίνεται τῇ ἀρχῇ τοῦ δρόμου τὸ τέλος. ἔνθεν καὶ περίοδος ὠνομάσθη, ἀπεικασθεῖσα ταῖς ὁδοῖς ταῖς κυκλοειδέσι καὶ περιωδευμέναις. καὶ καθόλου οὐδὲν ἡ περίοδός ἐστι πλὴν ποιὰ σύνθεσις. εἰ γοῦν λυθείη αὐτῆς τὸ περιωδευμένον καὶ μετασυντεθείη, τὰ μὲν πράγματα μένει τὰ αὐτά, περίοδος δὲ οὐκ ἔσται
Our words period, colon, and comma are just Greek words for lengths of clauses used as signs for those things in English. From the Oxford English Dictionary.
Demetrius, On Style 1
“…So too do things called kôla divide and clarify the language of prose”
οὕτω καὶ τὴν ἑρμηνείαν τὴν λογικὴν διαιρεῖ καὶ διακρίνει τὰ καλούμενα κῶλα
Demetrius, On Style 9
“This kind of brevity of speech in writing is called a komma. A komma is defined as shorter than a kôlon.”
ἡ δὲ τοιαύτη βραχύτης κατὰ τὴν σύνθεσιν κόμμα ὀνομάζεται. ὁρίζονται δ᾿ αὐτὸ ὧδε, κόμμα ἐστὶν τὸ κώλου ἔλαττον
Archilochus says it.
— Armand D'Angour (@ArmandDAngour) November 16, 2019
Autocorrect came for Armand’s grave and made it acute.
Here’s Archolochus fr. 120… συγκεραυνωθεὶς φρένας.
PSA: Colon (punctuation) vs. Colon (Intestine)
Greek kôlon (κῶλον) can mean body part (as in segment, member), so isocolonic can mean having equal-lengthed phrases or equal-lengthed limbs. But our colon (as in the segment between intestines and anus) comes from Greek kolon (κόλον). To make matters more confusing, later Greek, influenced by the closeness of the two, does present kôlon for the body part.
Here’s Beekes Etymological Dictionary 2010 on each: