“4. If God remains endlessly in ungenerated essence and the generate is endlessly generate, then the perverse doctrine of the homoousion and the homoiousion will be destroyed. And incomparability in essence is established when each of the two natures remains unceasingly in its proper rank of nature.
5. If God is ungenerated with respect to essence, what was generated was not generated by partition of essence, but he has made it to exist as a hypostasis by his power. For no pious reasoning permits the same essence to be generated and ungenerated.
6. If the ungenerated has been generated, what prevents the genrerated from having become generated? For every nature shuns what is improper to it for what is proper to it.
7. If God is not entirely ungenerated, nothing hinders him from having generated essentially. But if he is entirely ungenerated, he was not partioned essentially in generation, but he made the generate to exist as a hypostasis by his power.
8. If the ungenerated God is entirely generative, what was generated was not generated essentially, since his entire essence is able to generate but not to be generated. If the essence of God, having been transformed, is said to be generate, his essence is not unchangeable, since the change effected the formation of the Son. If the essence of God be unchangeableand superior to generation, relationship with the Son will be confessed to be a mere mode of address.”
10. If the generate was complete within the ungenerated,it is generate as a result of the things from which the ungenerrated generated it. This is false, for it is not possible that a generated nature be within an ungenerated essence. For the same thing is not able both to be an not to be. For a generate thing is not able to be ungenerated, and being ungenerated could not have been a generate thing, since to say that God consists of unlike parts presents to him the height of blasphemy of hybris.
“We have seen from our discussion of syllogisms #5 and #6 that Aetius based at least part of his argument against homoousion on the expectation that his opponents would agree to the axiom of God’s essential unity or simplicity. Certainly syllogisms #7 and #8 depend on this axiom. If God is admitted to be essentially compound, argued #7, then part of God’s essence could remin ungenerated while the other part would be able to become generated-or, as syllogism #8b put it ‘transformed’ into that which is generated. But since God is admitted not to be compound, if he is ungenerated, he must be entirely ungenerated (#7). On the other hand, the Christian tradiiton was unanimous in believing that he in some way caused the Son to exist as a separate entity. With partition ruled out, the only alternative left, reiterated Aetius, is that God’s essence created the Son, that ‘he made the generate to exist as a hypostasis by his power.’ (#7). Moreover, given God’s simplicity, the entire essence of God must have been involved in the creation of the son and, in that sense, to have been ‘entirely generative” (#8). The implicaiton was that God’s essence could have been generated in no sense whatsoever. Homoousion of the entirely generative one with the generated one is impossible. We see how crucial the assumption of God’s unity or simplicity was to Aetius arguments; this will become apparent once again when we consider syllogism #10.”
Thomas A. Kopecek, A History of Neo-Arianism, vol. 1, 231-232, 236.