The Father, Son, and Holy Spirit are in-generate in their inner and eternal being. Some want to think in terms of an origin of relation, and thus call the Father in-generate and the Son and Holy Spirit, following, generate. Here we get the notion of “eternal generation,” with the Father as the aitea or source of the Godhead. I affirm eternal generation, but only in a liminal way. That Father isn’t anymore the Father than the Son is the Son in relationship to the Father and vice-versa. This is a necessary and eternal relationship that resists, ultimately, the idea of generation and even in-generation.
I accept certain grammars in terms of heurisms, but then they break.
See my other recent post on the Trinity: click here