Wednesday, August 27, 2008


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.


1 comment:

StMichael said...

It is certain, and evident to our senses, that in the world some things are in motion.
Now whatever is in motion is put in motion by another, for nothing can be in motion except it is in potentiality to that towards which it is in motion; whereas a thing moves inasmuch as it is in act. For motion is nothing else than the reduction of something from potentiality to actuality. But nothing can be reduced from potentiality to actuality, except by something in a state of actuality. Thus that which is actually hot, as fire, makes wood, which is potentially hot, to be actually hot, and thereby moves and changes it. Now it is not possible that the same thing should be at once in actuality and potentiality in the same respect, but only in different respects. For what is actually hot cannot simultaneously be potentially hot; but it is simultaneously potentially cold. It is therefore impossible that in the same respect and in the same way a thing should be both mover and moved, i.e. that it should move itself. Therefore, whatever is in motion must be put in motion by another. If that by which it is put in motion be itself put in motion, then this also must needs be put in motion by another, and that by another again. But this cannot go on to infinity, because then there would be no first mover, and, consequently, no other mover; seeing that subsequent movers move only inasmuch as they are put in motion by the first mover; as the staff moves only because it is put in motion by the hand. Therefore it is necessary to arrive at a first mover, put in motion by no other; and this everyone understands to be God.