The Nicene Creed has more to say about the nature of the Trinity besides just that Jesus was eternally begotten. As well as that, I understand that the term “begotten” has a history going back to ancient Egypt in which it was a reference to Kingship, and that the term may still carry some of that meaning with it.
Aside from those things, the phrase still seems contradictory. I know that there are limitations when an idea needs to be expressed in words, hence the clarity of the Nicene Creed. Maybe this is just part of the mystery of the Trinity.
However, most of my question has to do with the apologetics that I’ve heard which describe a proof of sorts regarding God as a First Cause. If God is the first cause and the Son is eternal, to me, there is a seeming conflict. Is there a first cause before the Son was begotten? If so, how can the Son be eternal?