From a Trinitarian perspective, does the term 'only begotten Son' make sense outside of the concept of the incarnation? If so, how? If not, why not?
The Niceno–Constantinopolitan Creed states (in part):
We believe...in one Lord Jesus Christ, the only-begotten Son of God, begotten of the Father before all worlds... (emphasis added)
My question in extended form: Is the 'begotten-ness' eternal if and only if the incarnation is viewed from an eternal perspective as well (our sense of what begotten means would consequentially be inextricably linked to the incarnation) or is there some logic in conceiving that somehow a temporal locus of the incarnation imparts a distinction between it and 'eternally begotten'?
I imagine this is the sort of issue Thomas Aquinas would have considered - if so can someone direct me to how he addresses the issue.
I am also interested in the views of any other relevant trinitarian theologians as well.
This question: Is there any proof from the Bible that the second Person of the Trinity was the Only-begotten Son of the Father before His incarnation? is related but distinct.