Eternal sonship

1. I recently ran across the question of whether it's consistent to affirm the eternal sonship of Christ but disaffirm the eternal generation of Christ. To which I'd answer: yes!

2. Both sonship and generation are related metaphors, and so it might seem illogical to affirm one but disaffirm the other. But they're not identical metaphors. In addition, theological metaphors are analogies, and so the question is always how much to include in the analogy and what to exclude. What is the metaphor designed to illustrate? How far does the metaphor extend?

3. As I've discussed before, I think the significance of the sonship metaphor in reference to Christ is representational, in two related ways:

i) It's a way to indicate resemblance. Two things that could not be more alike but still be distinct. No one is more like a father than is son, or vice versa.

(Twin brothers might be a similar metaphor, but the father/son relation is far more dominant in the ancient world.) 

Which carries the implication that they are two of a kind. And, indeed, the NT often uses the sonship of Christ as a divine title.  The unique sonship of Christ implies the deity of Christ.

ii) If (i) is a metaphysical claim, that in turn has a practical aspect. Because they're so alike, there's a sense in which one can substitute for the other. A son can naturally act as his father's agent. Acting in on his behalf, in his place, with his authority. So (i) grounds (ii). Because the Son represents the Father ontologically, he's uniquely qualified to represent the Father in action. 

3. Turning to eternal generation, one asymmetry between eternal sonship and eternal generation is that the concept or metaphor of generation doesn't entail a son. Fathers beget daughters, too.  

Although generation is a male sexual metaphor in reference to the begetter, it is not a male sexual metaphor in reference to the begotten. Men father daughters as well as sons. And it would be inapt to say no one is more like a father than his daughter, pace the father/son relation. So that's one limitation of the metaphor or analogy. 

4. Unlike eternal sonship, eternal generation takes the metaphor a step further, as a theory of derivation. Eternal generation is a more radical and ambitious claim. In a sense, an attempt to explain the origin of the Trinity. On this view, the Father causes the Son and the Spirit to exist.

This is distinguished from creation in the usual sense inasmuch as they are eternally and necessarily caused to exist. Moreover, they share the Father's essence. 

Whether that's adequate to distinguish God from a creature is disputable. By that logic, the Father could be eternally and necessarily caused to exist by a super-deity who stands behind the Trinity, transmiting his essence to the Father. Indeed, the logic of the principle seems to extend backward with no stopping-point. 

Of course, some folk's ecclesiology commits them to creedal statements regarding eternal generation. I appreciate the fact that the Nicene paradigm squeezed out Arianism, but I regard eternal generation as a theological compromise or halfway house that degrades the deity of the Son and Spirit. In that respect I side with theologians like Alexander Röell, B. B. Warfield, Paul Helm, and John Frame who reject a hierarchical model of the Trinity.