Schema

I got this schema from Scott MacDonald's article "The Esse/Essentia Argument, ect." in Thomas Aquinas: Contemporary Philosophical Perspectives - I thought this was cool enough to load right away. This is the schema of Saint Thomas Aquinas' argument in De Ente et Essentia 4 which argues for a certain metaphysical distinction he is known for (the "real" distinction), and thus proves the existence of God as esse subsistens or "an act of existing which subsits."
Key: "essence" is the principle that makes any entity be "that sort of" entity - it is "what" that thing is.
"esse" is the Latin word for "to be." It is the corresponding principle to "essence" in any entity and it causes that entity to exist.

Here's the schema of the argument:

1. Whatever belongs to a thing and is not part of its essence either
1. Come from without and effects a composition with the essence or
2. Itself constitutes the entire essence
2. No essence can be understood without its parts
3. Every essence [except the Divine essence] can be understood without anything being understood about its esse
4. A thing’s esse is not part of its essence
5. Suppose that there is something [X] which is esse alone, as esse subsistens
6. Pluralization occurs in one of only three ways:
1. By the addition of some differentia,
2. By a form being received in different matters, or
3. By onething being absolute and another being received in something.
7. Anything which is esse alone cannot receive the addition of differentia
8. X cannot be more than one in virtue of F(a)
9. Anything which is esse alone cannot receive different matters
10. X cannot be more than one in virtue of F(b)
11. If there is anything which is its own esse, there is at most one such thing.
12. For any other thing besides this one, its esse is other than its essence.
13. These Y entites are entities other than this esse subsistens.
14. There is esse besides essence in Y entities
15. Everything which belongs to something either
1. Is caused by the principles of its nature or
2. Comes to it from some extrinsic principle.
16. A thing’s esse cannot be caused by the thing’s essence [ie, a thing’s esse is not accounted for by O(a)] because it is impossible that a thing produce itself in esse/
17. It must be that every thing such that its esse is other than its essence has esse from another [ie, a thing’s esse is accounted for by O(b)].
18. One cannot go to infinity in efficient causes.
19. There is something which is the cause of esse for all things in virtue of the fact that it is esse alone.
20. Everything which receives something from another is in potentiality with respect to what is received, and what is received is the actuality of the thing.
21. All things [other than God] are in potentiality with respect to the esse which they receive from God.
22. Potentiality and actuality are found in Y entities.

*Bold = conclusions

I want to come back and talk about the metaphysical underpinnings of this argument, analyzing its assumptions.

Later!