The Contents of a Foundational Mind (Or: A Weird Objection I Found on the Internet)

I recently came across somebody who argued that the foundation of reality could not be a mind, because if it were, then this mind would have no referent beyond its own existence (no "intrinsic content," as they put it). This would (supposedly) prevent the foundational mind from proceeding beyond its initial state. 

I must say, this strikes me as obviously wrong. After all, if God exists, and is omniscient, then He presumably has perfect modal knowledge; that is to say, even before the moment of creation, God knew all possible worlds that He could actualize. How might God know/have known this? Well, one potential answer is that modality is grounded in divine power. This would allow God to have perfect modal knowledge simply by knowing Himself, and specifically, His own power to actualize various states of affairs.

Indeed, classical theism has traditionally held that God's knowledge is rooted in His knowledge of Himself. For instance, here's what Aquinas has to say on the matter:

Inasmuch as He knows His own essence perfectly, He knows it according to every mode in which it can be known. Now it can be known not only as it is in itself, but as it can be participated in by creatures according to some degree of likeness. But every creature has its own proper species, according to which it participates in some degree in likeness to the divine essence. So far, therefore, as God knows His essence as capable of such imitation by any creature, He knows it as the particular type and idea of that creature; and in like manner as regards other creatures. So it is clear that God understands many particular types of things and these are many ideas. (ST I.15.2)

And of course, one does not need to be a Thomist to accept my initial point (i.e. that God could have perfect modal knowledge simply by knowing His own power).