[Tom McCall] asserts unambiguously, "Hard EFS entails the denial of the homoousion." He argues:
(1) If Hard EFS is true, then the Son has the property being functionally subordinate in all time segments in all possible worlds.
(2) If the Son has this property in every possible world, then the Son has this property necessarily. Furthermore, the Son has this property with de re rather than de dicto necessity.
(3) If the Son has this property necessarily (de re), then the Son has it essentially.
(4) If Hard EFS is true, then the Son has this property essentially while the Father does not.
(5) If the Son has this property essentially and the Father does not, then the Son is of a different essence than the Father. Thus the Son is heteroousios rather than homoousios.
[Philip R. Gons and Andrew David Naselli, "Three Recent Philosophical Arguments against Hierarchy," in Bruce A. Ware and John Starke, eds., One God in Thee Persons: Unity of Essence, Distinction of Persons, Implications for Life (Wheaton, IL: Crossway, 2015), 198]
In the same way, then, the historic doctrines of the eternal generation of the Son and the eternal procession of the Spirit, which the majority of the church has embraced in the East and the West since at least the Council of Nicaea in 325 and arguably much earlier, would entail the denial of homoousion. We could restate McCall's argument this way:
1. If the Nicene doctrine of the Trinity is true, then the Son has the property generate in all time segments in all possible worlds.
2. If the Son has this property in every possible world, then the Son has this property necessarily. Furthermore, the Son has this property with de re rather than de dicto necessity.
3. If the Son has this property necessarily (de re), then the Son has it essentially.
4. If the historic doctrine of the Trinity is true, then the Son has this property essentially while the Father does not.
5. If the Son has this property essentially and the Father does not, then the Son is of a different essence than the Father. Thus the Son is heteroousios rather than homoousios.
If the argument is valid, not only does it refute EFS's proposal that the distinction between the Father and the Son is best understood in terms of authority and submission, but it also refutes the view held by the vast majority of the church for at least the last seventeen hundred years, namely, that the Father, Son and Spirit possess unique personal properties that distinguish them from one another.
If what McCall and Yandell argue is true, then the church's best theologians, the very ones who defined and defended homoousion, unknowingly denied it and differed only slightly from Arians. The entire history of orthodox Trinitarianism was unknowingly heterodox for the simple reason that its view of the Trinity entails a denial of homoousion. That is a weighty charge.
The primary argument against EFS it seems is to make it a matter of ontological subordination. But the question always is "where's the proof?". Given that EFS proponents have always affirmed ontological equality between the persons, the onus is on their accusers to prove their case that their affirmation is invalid.
One particular argument it seems is that predicating submission of the Son in eternity implies that it belongs to the being of the Son to be subordinate to the Father. Thus argues Tom McCall. But as Gons and Naselli pointed out, the same argument would implicate Nicene Orthodoxy itself when applied consistently. The key error in McCall's reasoning is to equivocate on the term "essential" (Ibid., 201). The first meaning is that of necessity, "essential to being something." The second meaning is that it pertains to the essence of a thing, "what a thing is." By equivocation, McCall's argument makes an invalid argument in an effort to promote his view of radical egalitarianism.
I would of course disagree that "the distinction between the Father and the Son is best understood in terms of authority and submission." But I do not deny such a distinction. That the Father has personal properties that the Son does not have is basic Nicene Orthodoxy: the Father unbegotten, the Son begotten. But the way Nicene Orthodoxy goes about is to say that the predication of the persons have no bearing on the being (the essence) of God. In being, in ontology, the three persons share the one Godhood, and all are the one God, equal in power and glory. BUT in persons, they posses personal properties that are not shared among the persons. The Father does not share in the property "begotten," for example. There is thus an asymmetry in the relations of the Godhead. To claim otherwise is to reject Nicene orthodoxy.
Functions of authority and submission only work in dynamic relations, and thus they can only be predicated of the works of the persons. Therefore, they must be predicated of God ad extra. The relations of eternal generation and eternal procession of the Son and the Spirit respectively are stative concepts, in that they pertain immutably to God ad intra. But to speak of the eternal submission of the Son from the pactum salutis in eternity past is to envision a dynamic interaction of the Son covenanting with the Father for the salvation of the elect. Gons and Naselli did not quite make the distinction, but a distinction between the ad intra and ad extra would be very helpful here as it introduces another layer of distinction and nuance into the relations within the Godhead. It would certainly avoid more confusion over people thinking that EFS has to do with ontology when it has absolutely nothing to do with ontology. Evidently, the critics think they know better what the proponents believe about EFS than the proponents do themselves.
Regardless, I think Gons and Naselli has pointed out one fatal flaw among those who deny EFS. Can the doctrine of God espoused by EFS critics survive the reductio ad absurdum pointed out by Gons and Naselli? If they could, how? After all, it seems that if everything is about BEING, then the Son must be subordinate to the Father if he is really begotten of the Father. Or perhaps, we can stop being so obsessed with ontology. But I'm not holding my breath for EFS critics to actually respond. After all, misrepresentation and demonization is always easier, especially when the opponent is "Big Eva"!