Having proved to his satisfaction that it is possible for a created intellect to see the essence of God, St. Thomas goes on to ask whether this vision happens by way of a similitude in the created knowing power. Properly understood, the question is startling. Of course we do have a similitude in our minds (i.e. an idea) when we know God. The question is exactly like asking whether we have an aroma in our noses when we smell something, our sound waves in our ears when we’re hearing something. Obviously we have an idea of God when we know him. But then St. Thomas denies that this is the case. “Idea” or “likeness” is a means created in us by which we see something other, but God, even if he is other, cannot be known by such a thing. Three arguments are given for this:
1.) Lower orders cannot make higher orders known in themselves. If I have a friendship of virtue, I can feel what is desirable in friendships of pleasure, since virtue is itself pleasant. But the same does not work the other way, because not everyone who experiences pleasure also knows virtue by experience. Lower forms of experience or awareness cannot make higher ones manifest, and so much more is it impossible for any created likeness to make God himself known.
2.) Created forms have existence from another, and God does not. No created form can is therefore a likeness of God, which is exactly what it would have to be if we knew God by a likeness.
3.) A created form must be a determinate logos, a this as opposed to a that. Even our logos of being is distinguished from the logos of truth. But the divine essence is purely uncircumscibed, a logos which contains within a single idea all that is in creatures.
And so the conclusion is that the divine essence itself unites itself to the intellect to be known. It is as though instead of knowing all physics we became the very laws themselves and all the possible interactions that have or could ever arise from them. But if this is the right analogy, then what is the status of the beatific vision as a moment in theology?