This isn’t an empirical corpus study of μονογενής. It isn’t comprehensive or thorough; it’s just a handful of examples that popped out at me while looking at instances of μονογενής in Koine texts. At best these are anecdotes. Still, I thought it would be worth doing something as a follow up on my previous post on method and native speakers. I refused to speculate on the meaning of μονογενής there. While I still have no intention of drawing a hard conclusion, I did think it might be worth a few moment to look through some Koine texts to see what I’d find.

I can understand why μονογενής could be justifiably translated as ‘only begotten’ in contexts like  Judges 11:34, where μονογενής is the head noun.

• Καὶ ἦλθεν Ιεφθαε εἰς Μασσηφα εἰς τὸν οἶκον αὐτοῦ, καὶ ἰδοὺ ἡ θυγάτηρ αὐτοῦ ἐξεπορεύετο εἰς ἀπάντησιν αὐτοῦ ἐν τυμπάνοις καὶ χοροῖς, καὶ αὕτη μονογενὴς αὐτῷ ἀγαπητή, καὶ οὐκ ἔστιν αὐτῷ πλὴν αὐτῆς υἱὸς ἢ θυγάτηρ.
  And Jephthah went to Mizpah to his house; and behold, his daughter was going out to meet him with drums and dancing. She was his μονογενὴς beloved; there was not another son or daughter to him.

My big question would be:

What’s the benefit of maintaining ‘begotten-ness’ for biological contexts in texts where μονογενής is modifying ‘child’ or ‘son’ or daughter’ What’s its semantic contribution in such cases?

Consider the following:

• Psalms of Solomon 18:4
  ἡ παιδεία σου ἐφʼ ἡμᾶς ὡς υἱὸν πρωτότοκον μονογενῆ ἀποστρέψαι ψυχὴν εὐήκοον ἀπὸ ἀμαθίας ἐν ἀγνοίᾳ
  Your instruction is upon us as a first-born μονογενῆ son to divert the obedient soul from ignorance in sins.

So this text has, “first born μονογενῆ son.” That’s a lot of redundancy if μονογενής means ‘only begotten.’

Another interesting example is from Josephus, Antiquities 2.181, where the contrast is on quantity rather than ‘begotten-ness’ in the context of Josephus retelling of the Old Testament historical books:

• καὶ τὸ μὲν γνήσιον γένος τῷ Ἰακώβῳ τοῦτο ἦν, ἐκ Βάλλας δὲ αὐτῷ γίνονται τῆς Ῥαχήλας θεραπαινίδος Δάνος καὶ Νεφθαλίς, ᾧ τέσσαρες εἵποντο παῖδες, Ἐλιῆλος Γοῦνις Σάρης τε καὶ Σέλλιμος, Δάνῳ δὲ μονογενὲς ἦν παιδίον Οὖσις.
  This was the children born to Jacob in wedlock. And from Balla (i.e. Bilhah), the maidservant of Rachel, there were born to him Dan and Nepthali, from whom four children were born—Eliel, Gunis, Sares, and Sellim. Dan had an μονογενὲς child, Usi.”

Dan has a single son. Nepthali has four. Are Nepthali’s less ‘begotten’ somehow?

This other example from Josephus is also quite striking (Antiquities 20.20):

• ἦν δὲ αὐτῷ Μονόβαζος τούτου πρεσβύτερος ἐκ τῆς Ἑλένης γενόμενος ἄλλοι τε παῖδες ἐξ ἑτέρων γυναικῶν. τὴν μέντοι πᾶσαν εὔνοιαν ὡς εἰς μονογενῆ τὸν Ἰζάτην ἔχων φανερὸς ἦν.
  He [Bazeus king of Adiabene] had [the son] Monobazos, his [Izates] elder brother also from Helena, and he had other sons by other wives additionally. Yet he [Bazeus] openly placed all his affections on this his μονογενῆ Izates.

Seems that something like ‘particularly special’ or ‘preferred/favorite’ would be best here.