Scotus points to a sort of 20-Questions game that starts with a guy saying “I’m thinking of something that exists” according to the rules of the game, you know the thing exists, but you don’t know if it’s God or a creature, substance or accident, instrument or agent, etc.
St. Thomas, however, seems to think that all indetermination in thought has to reduce to some indetermination in things, or that a generic thought has to correspond to some potency in things.
that from which the difference constituting the species is derived, is always related to that from which the genus is derived, as actuality is related to potentiality. For animal is taken from the sensitive nature by way of concretion, since a thing is called an animal when it has a sensitive nature; or rational when it it has an intellectual nature. [Animal enim sumitur a natura sensitiva per modum concretionis; hoc enim dicitur animal, quod naturam sensitivam habet, rationale vero sumitur a natura intellectiva, quia rationale est quod naturam intellectivam habet]
The same argument holds good in other things
ST. 1.4.5. co
So logical determinations are seen as real natures “in modo concretionis” which STA takes as equivalent to saying that a thing has some real nature. Thus there is no indeterminate concept which is not at least the attempt to speak about some indeterminate nature.
But then what do we say about the twenty-questions game? Presumably STA wouldn’t deny that you could play the game, but only that the thought you started with was of real existence. Perhaps he’s call it a failed attempt to visualize existence or a counter-factual visualization of existence; one that could only be true if God had a divine nature instead of being it.
This is the foundation of the strange Thomistic claim that God is beyond being.