33.45
The future indicative predominantly refers to an action that is situated in the ‘actual’ future relative to some other moment (in main clauses, the moment of speaking), as in (64)–(67). The future indicative may, however, also be used to express: – hypothetical scenarios and general truths (cf. Engl. If A is larger than B, B will be smaller than A; Oil will float on water); – inferences (cf. Engl. That’ll be the postman).
In such cases the realization of the action does not necessarily lie in the future; rather, the sense underlying the use of the future indicative is that the truth of the statement will be ascertainable at some future moment (if reasoning is followed to its logical conclusion, or if evidence becomes available):
(68) λείπεται δὴ ἐκεῖνος μόνος . . . φίλος τῷ τοιούτῳ, ὃς ἂν ὁμοήθης ὤν . . . οὗτος μέγα ἐν ταύτῃ τῇ πόλει δυνήσεται, τοῦτον οὐδεὶς χαίρων ἀδικήσει. οὐχ οὕτως ἔχει; (Pl. Grg.510c)
The only possible friend that remains for such a man (a tyrant) is whoever shares his temper. That man will have great power in that city, and no one will wrong him with impunity. Isn’t that right? This passage concludes a section of a (hypothetical) argument about how someone can avoid being wronged. The future indicative presents the conclusion as the logical outcome of the argument. Note the assent-seeking question οὐχ οὕτως ἔχει; (with a present indicative), by which Socrates asks his interlocutor to confirm that the reasoning holds.
(69) Ἄκουε δή, ἦ δ’ ὅς. Φημὶ γὰρ ἐγὼ εἶναι τὸ δίκαιον οὐκ ἄλλο τι ἢ τὸ τοῦ κρείττονος συμφέρον. ἀλλὰ τί οὐκ ἐπαινεῖς; ἀλλ’ οὐκ ἐθελήσεις. Ἐὰν μάθω γε πρῶτον, ἔφην, τί λέγεις· νῦν γὰρ οὔπω οἶδα. (Pl. Resp. 338c)
‘So listen’, he said. ‘I claim that justice is nothing other than what is beneficial for the stronger. Why aren’t you applauding my claim? Well, I suppose you won’t want to.’ ‘Yes I do’, I said, ‘if only I learn first what it is that you mean. For I don’t know that yet now.’ On the basis of their preceding conversation, Thrasymachus draws an inference about Socrates’ unwillingness to agree with him. Socrates challenges that inference in his reply.