A dilemma put by Eunomius was the following:  When God begat the Son, the Son either was or was not. Ητοι ὄντα ἐγέννησεν ὁ Θεὸς τὸν Υιὸν, ἢ οὐκ ὄντα.  If He was not, no argument could lie against Eunomius and the Arians.  If He was, the position is blasphemous and absurd, for that which is needs no begetting. Id. ii. 14.