Philosophical theology, it seems, is often a matter of choosing the least misleading image.
Consider these options: "God knows something because it happens" vs. "Something happens because God knows it." The latter might seem problematic, since, among other things, it can seem to make freewill problematic. (Indeed, as we have seen, because Boethius affirms the latter at the very end of the Consolation, Marenbon is even tempted by an ironic reading of the work.) But if the latter is problematic, the former is even more problematic.
Suppose God knows something because it happens. (i) Then did it happen first, without God's knowing it? Then God would either not be omnipotent, or not an intelligent cause. Also, (ii) God's knowing it, since this is a consequence of the thing's happening, would seem to be a matter of some pathos in God, and thus God would not be an entirely actualized being--in which case he would not be a first cause. Also, (iii) when something changes, God's knowledge would seem to change, and thus God would exist in time. Also, (iv) if its happening were prior to God's knowing it, then, it seems, it could in principle happen without God's knowing it, which would seem to imply that God requires a medium for knowing it.
I think Boethius is aware of these difficulties and gestures at them briefly (in the highlighted phrase):
So that the difficulty you put forward a short time ago, that it was unfitting if our future is said to provide a cause of God's knowledge, is solved. The power of this knowledge which embraces all things in present understanding has itself established the mode of being for all things and owes nothing to anything secondary to itself.Yet note that Boethius says more than that the alternative is unacceptable. He says actually that he has solved (or dissolved: resoluitur) that difficulty also. That is, he thinks that, in dissolving the difficulty about divine foreknowledge and human freedom, he has thereby dissolved the difficulty about divine omnipotence and human freedom.
42. ex quo illud quoque resoluitur quod paulo ante posuisti, indignum esse si scientiae dei causam futura nostra praestare dicantur. 43. haec enim scientiae uis praesentaria notione cuncta complectens rebus modum omnibus ipsa constituit, nihil uero posterioribus debet.
And it makes sense that he would think this, because both difficulties would appear to arise in the same way. We suppose that God's foreknowledge of future human actions implies that we are not free, because we imagine that God is constrained to know the future in the same way that we do, when we know something in the future (i.e. by tracing forward necessitated chains of cause and effect). Similarly, we suppose that God's power over future human actions implies that we are not free, because we imagine that God is constrained to affect the future, in the same way that we are, when we control something future, viz. by changing something in the past, which necessitates that the thing about to happen in the future will proceed differently from how it would have happened on its own.
Note also that the main theme of book III had been that God suaviter omnia disponit: that God acts on nature precisely without that sort of violence. Marenbon's interpretation in effect demands that Boethius take up this theme all over again. Indeed, Marenbon can get the problem going only by stating it in such a way that it presupposes that created things do not have their own natures. Marenbon wrote:
Although Philosophy considers that she has successfully resolved the character Boethius's problems, the reader is left asking whether this final concession, which makes God the determiner of all events, does not ruin the elaborate defence of the contingency of human volitions she has just been mounting.But Boethius is not an occasionalist. He denies that natures can be analyzed into bundles of 'events'. For Boethius, God does not cause 'events', which somehow constitute or are taken to constitute natures. God causes things qua having natures, and among these are rational natures.