E. M. Cope, Commentary on the Rhetoric of Aristotle

συνθῆκαι καὶ συμβολαί] On συμβόλαια and συναλλάγματα see above, note on I 1, 10 p. 16.

συνθήκη is a general term for a treaty, compact, contract, convention, usually of a public nature, between two states, but also all private contracts, covenants, and bargains; see Rhet. I 15, 20—23, περὶ συνθηκῶν. σύμβολα—here called συμβολαί, apparently a ἅπαξ λεγόμενον in this sense; in Pol. III 9, 1280 a 38, συνθῆκαι and σύμβολα are contrasted—are technically confined by the grammarians to a particular and special kind of contract, international commercial treaties. Meier ü. Schömann, Att. Process, p. 494, note 49. In the passage referred to, σύμβολα first occurs apparently in its proper sense, πάντες οἷς ἔστι σύμβολα πρὸς ἀλλήλους: and then, as distinguished from συνθῆκαι, which here stand for commercial treaties in general, συνθηκαι περὶ τῶν εἰσαγωγίμων, seems to be applied to those special and subordinate articles of commercial contracts which made provisions against the infliction of mutual damage and wrong, or established a system of compensation which protected the contracting parties against mutual injury, σύμβολα περὶ τοῦ μὴ ἀδικεῖν. In the usual sense, Pol. III 1, 1275 a 9, τοῦτο γὰρ ὑπάρχει καὶ τοῖς ἀπὸ συμβόλων κοινωνοῦσιν, ‘even the members of different states who are connected by international commercial treaties have reciprocal legal rights, so that it cannot be this which constitutes a citizen’. In Thuc. I 77, the ξυμβόλαιαι πρὸς τοὺς ξυμμάχους δίκαι denote the actions at law which arise out of these ξύμβολα. Dem. c. Mid. 570, τὰ σύμβολα συγχέων. See Buttm.'s Ind., s. v.

πρὸς δύο γὰρ διαφυλάττειν κ.τ.λ.] ‘for there are two classes of persons between whom and the citizens it is necessary that irreproachable conduct or behaviour, or a thoroughly good understanding, should be steadily, persistently (διά, thoroughly, throughout), maintained’.