Plato, Laws 814a

καὶ τάξεων καὶ θέσεως καὶ ἀναιρέσεως ὅπλων ἡμμένας, εἰ μηδενὸς ἕνεκα, ἀλλʼ εἴ ποτε δεήσειε πανδημεὶ πάσῃ τῇ δυνάμει καταλείποντας τὴν πόλιν ἔξω στρατεύεσθαι, τοὺς φυλάξοντας παῖδάς τε καὶ τὴν ἄλλην πόλιν ἱκανοὺς εἶναι τό γε τοσοῦτον, ἢ καὶ τοὐναντίον, ὧν οὐδὲν ἀπώμοτον, ἔξωθεν πολεμίους εἰσπεσόντας ῥώμῃ τινὶ μεγάλῃ καὶ βίᾳ, βαρβάρους εἴτε Ἕλληνας, ἀνάγκην παρασχεῖν περὶ αὐτῆς τῆς πόλεως τὴν διαμάχην γίγνεσθαι, πολλή που κακία

and shouldering of arms,— and that, if for no other reason, at least for this reason, that, if ever the guards of the children and of the rest of the city should be obliged to leave the city and march out in full force, these women should be able at least to take their place; while if, on the other hand—and this is quite a possible contingency—an invading army of foreigners, fierce and strong, should force a battle round the city itself,