Today we’re going to fix two problems with the verb conjugations in the old grammars. Click on afairisetai and look at what the Word Tool tells you.
τῆς γὰρ ἐμπορίας οὐκ οὔσης, οὐδ᾽ ἐπιμειγνύντες ἀδεῶς ἀλλήλοις οὔτε κατὰ γῆν οὔτε διὰ θαλάσσης, νεμόμενοί τε τὰ αὑτῶν ἕκαστοι ὅσον ἀποζῆν καὶ περιουσίαν χρημάτων οὐκ ἔχοντες οὐδὲ γῆν φυτεύοντες, ἄδηλον ὂν ὁπότε τις ἐπελθὼν καὶ ἀτειχίστων ἅμα ὄντων ἄλλος ἀφαιρήσεται, τῆς τε καθ᾽ ἡμέραν ἀναγκαίου τροφῆς πανταχοῦ ἂν ἡγούμενοι ἐπικρατεῖν, οὐ χαλεπῶς ἀπανίσταντο, καὶ δι᾽ αὐτὸ οὔτε μεγέθει πόλεων ἴσχυον οὔτε τῇ ἄλλῃ παρασκευῇ.
It’s a real mish-mash, isn’t it? How could a verb simultaneously be so many things? Well, the verb isn’t the issue at all, it’s the spelling. In the old grammars, that spelling shows up in three separate sections on conjugation. Actually, this happens in English, too; “I set the dish down” vs “I can set the dish down”, one of which is probably past tense and the other sort of a future tense.
Context is king when you want to know the meaning; morphology alone won’t get you there.
Let’s deal with the first one first. Here’s our aspect table again.
ASPECT FLAVOR => eventive conceptual
Imperfective
Progressive
Perfective
Based on what the word tool tells you, afairisetai could belong in the last row as “future perfect”. Because it’s labeled “future”, you might think it goes in the conceptual column where the old “future tense” belongs. Because it’s labeled “perfect” you might think it goes in the bottom row – but that position is already populated by the morphology formerly known as “perfect tense”.
And in fact Goodwin, page 156, section 704 says that “future perfect” is passive voice. The only reason this verb form was labeled “perfect” is because in Attic Greek it has the same reduplication as the perfect and pluperfect tenses (perfective conceptual and eventive in our schema). You can see this in White, page 241, section 770, alongside the imperfective passive.
Remember, only imperfective has a passive in non-mai verbs; progressive and perfective aspects do not have a passive. With -mai endings, verbs have only passive and base voices.
Now remember that you use passive structures for complete intransitivity. This subsection of Thucydides refers to strangers showing up and taking away produce of those who settled the Peloponnese ahead of the Hellenes. By definition, if you take X away, you have a transitive structure. So “future perfect” or “imperfective conceptual passive,” that’s the wrong label to assign this verb in this context.
The second choice is imperfective conceptual indicative in base voice. That has the nuance that the taking would not be deliberate; I hope you can come up with a citation to a context where it is used that way. While technically it’s a form you could generate, that doesn’t mean any surviving texts use it. Same thing happens in Biblical Hebrew.
That leaves only one option, and that gets us into the subject of modality (formerly known as “mood”).