With regard to the question “whats the difference between a property and a relation?”: I have trouble understanding what the difference is myself. Maybe someone else who has a better grasp of Thomas’s view can help out here. Personally, I take it that relations “connect” property-bearers according to their properties. The relation “taller than” relates a thing that is six inches tall to something that is three inches tall.

But how the “relation” of Fatherhood connects the Father to the Son, I don’t know. For Thomas the Father and Son have identical essential properties and no accidental properties. So why the Father is the Father of the Son and the Son is not the Father of the Father… again, I don’t know. I don’t endorse Thomas’s view, I’m just trying to understand it.

With regard to your question about “epistemically individuating features,” I guess I should have just said “individuating features.” I don’t think there can be anything which is merely epistemically individuating. If a thing individuates something from something else, then it both metaphysically and epistemically individuates that thing.

Anyway, I’m sure there are much better defenders of Thomistic Latin Trinitarianism out there. I’d personally like to get a better grasp of the view. For my part, I can’t make sense of how mere relations (without any underlying property differences) individuate any two things.

Could you explain this a bit more:
“the proponent of simplicity is forced to argue that the fatherhood of the father is not a real property but, entirely a relation.” What’s the difference here btwn. a property and a relation?

Also, you write:
“The same goes for the “epistemically individuating” features of the Son and the Spirit; they are distinguished by relations, not properties.”

By saying “epistemically individuating” are you saying that there are no ‘real’ features that distinguish one divine person from another? A relation might do it — but it remains to be seen just how you understand Aquinas’s theory of relations in this context.

Anyway, I wonder whether a defender of simplicity would want to say that the Son inherits the Father’s “properties” seeing as simple beings don’t have properties, per se.

As I understand this problem (more so through Thomas than Athanasius) the proponent of simplicity is forced to argue that the fatherhood of the father is not a real property but, entirely a relation. The same goes for the “epistemically individuating” features of the Son and the Spirit; they are distinguished by relations, not properties.

The big problem, I think, for this view is that the relations (like the relation of fatherhood which uniquely relates one divine person from another divine person with identical properties) is that it hangs on nothing. There is no underlying monadic property difference on which the relation subsists.

Of course, the relation “taller than” could not possibly relate two persons who are exactly the same height, so I don’t understand how this mysterious relation is supposed to individuate the Father as the Father in relation to the Son. But, as I understand it, the advocate of simplicity won’t grant that there is a property called “fatherhood” that is had by the first person of the Trinity.