Thucydides: 3.9

Yes I know I am not exactly steaming through Thucydides book 3 but in my defense my time currently is not my own, unfortunately. That said, I am not liking my grammatical analysis of this sentence (the opening lines of the Mytilenian speech to the Spartans and their allies at Olympus). I understand what is being said but I am slightly puzzled by the sentence’s construction:

[3.9]
τὸ μὲν καθεστὸς τοῖς Ἕλλησι νόμιμον, ὦ Λακεδαιμόνιοι καὶ ξύμμαχοι, ἴσμεν· τοὺς γὰρ ἀφισταμένους ἐν τοῖς πολέμοις καὶ ξυμμαχίαν τὴν πρὶν ἀπολείποντας οἱ δεξάμενοι, καθ’ ὅσον μὲν ὠφελοῦνται, ἐν ἡδονῇ ἔχουσι, νομίζοντες δὲ εἶναι προδότας τῶν πρὸ τοῦ φίλων χείρους ἡγοῦνται.

[ generic but problematic translation ]

We know the established custom among the Hellenes: that those who in time of war desert and abandon their previous alliance are favorably received so far as they are of use, but seeing that they are traitors to their former fields they are actually considered worse.

The issue for me is actually the force of ‘οἱ’. I am taking it is masc nom plural.

So in a more literal translation I would write:

"Those who in the time of war desert and abandon their previous alliance, others favorably receive as long as they enjoy some profit from it but in reality they consider them actually worse because they believe them to be traitors of their old friends.

But there is a suggestion that ‘οἱ’ is dat singular (Homeric/Ionian form). I am not entirely convinced that is true.

Thoughts?

it has to be nominative plural, surely… those who have received them, which is the subject of ἔχουσι and νομίζοντες… ἡγοῦνται. Unless I’m missing something…

I am with you on this but like you I just might be missing something here … thanks!

Yes, οἱ δεξάμενοι is just “those who receive them." Then the sentence forks—μὲν … δὲ:
“to the extent that they’re being benefitted (καθ’ ὅσον μὲν ὠφελοῦνται) they’re pleased to have them" (lit. they hold them in pleasure, ἐν ἡδονῇ ἔχουσι),
"but considering them to be traitors to their former friends (νομίζοντες δὲ εἶναι προδότας τῶν πρὸ τοῦ φίλων) they think them worse” (i.e. they think less of them, they hold them in less favorable regard).
It’s unusually well balanced for Thucydides.

Thank you.