Divine-Human Operation

In a lecture on incarnation and kenosis, Princeton’s Bruce McCormack asks John of Damascus how he can say that every act of the God-Man is “100% human and 100% divine.” Won’t the omnipotent divine act overwhelm the human act?

That’s an odd question, I think. For, given divine concurrence, the question arises not only with the incarnate Christ but with every human act; how can any human act be human, how can any avoid being “overwhelmed” by divine action? I’m not eliminating the radical difference between the works of the divine-human Jesus and other humans; but in both cases we are dealing with a combination of divine and human activity, are we not?

Behind this seems to be the assumption that divine action is at the expense of human action. But why should that be? Also behind the question seems to be the notion that human action might, possibly, be independent of divine action and divine gift. But that is certainly not the case.