Herbert Weir Smyth, A Greek Grammar for Colleges

ὁ, ἡ, τό AS A DEMONSTRATIVE IN ATTIC PROSE

[*] 1107. ὁ is a demonstrative commonly before μέν, δέ, and especially in contrasted expressions: ὁ μέν . . . ὁ δέ the one, this . . . the other, that, as in ““οἱ μὲν ἐπορεύοντο, οἱ δ᾽ εἵποντο” the one party proceeded, the other followed” X. A. 3.4.16.

[*] 1108. The reference may be indefinite; in which case τὶς is often added: ““τοὺς μὲν ἀπέκτεινε, τοὺς δ᾽ ἐξέβαλεν” some he put to death, and others he expelled” X. A. 1.1.7, οἱ μέν τινες ἀπέθνῃσκον, οἱ δ᾽ ἔφευγον some were killed, but others escaped C. 3. 2. 10.

[*] 1109. With prepositions the order is usually inverted: ἐκ μὲν τῶν, εἰς δὲ τά (1663 a).

[*] 1110. In late writers (but in Demosthenes) the relative is used as in 1107: πόλεις, α_<*>ς μὲν ἀναιρῶν, εἰς α_<*>ς δὲ τοὺς φυγάδας κατάγων destroying some cities, into others bringing back their exiles D. 18.71 (the first instance).

[*] 1111. Note the adverbial expressions: τὸ (τὰ) μέν . . . τὸ (τὰ) δέ on the one hand . . . on the other hand, partly . . . partly (so also τοῦτο μέν . . . τοῦτο δέ 1256); τὸ δέ τι partly, τῇ μέν . . . τῇ δέ in this way . . . in that way, τὸ δέ whereas (1112), τῷ τοι therefore.

[*] 1112. ὁ δέ, ἡ δέ, τὸ δέ (without a preceding μέν clause) often mean but (or and) he, she, this. In the nominative the person referred to is usually different from the subject of the main verb: Κῦρος δίδωσιν αὐτῷ μυ_ρίους δα_ρεικούς: ὁ δὲ λαβὼν τὸ χρυ_σίον κ.τ.λ. Cyrus gives him (Clearchus) 10,000 darics; and he taking the money, etc. X. A. 1.1.9, ταῦτα ἀπαγγέλλουσι τοῖς στρατιώταις: τοῖς δὲ ὑποψία_ ἦν ὅτι ἄγοι πρὸς βασιλέα_ they report this to the soldiers; and they had a suspicion that he was leading (them) against the king X. A. 1.3.21, ““τὸ δ᾽ οὐκ ἔστι τοιοῦτον” whereas this is not so” P. A. 37a.