In the previous post I offered the outline for a possible argument for a causal proposition. Here is the basic, five-premise outline:

1. Everything real is either subsistent or dependent on another
2. The existence of finite things is not subsistent
3. Therefore the existence of finite things is dependent on another
4. Whatever is dependent on another is caused by another
5. Therefore, the existence of finite things is caused by another

In that post I offered also the outline for a defense of the first premise. Here I will do the same for the second premise, that the existence of finite things is not subsistent. These first two are the two crucial premises.

1. Whatever is a part of a whole, in such a way that it cannot exist on its own apart from the whole, is non-subsistent
   1. Whatever is a part of a whole, in such a way that it cannot exist on its own apart from the whole, is dependent on the whole for its existence
   2. Whatever is subsistent is/has what is sufficient for its existence on its own
   3. Whatever is dependent for its existence on something else, does not have what is sufficient for its existence on its own
   4. Therefore whatever is dependent for its existence on something else, is non-subsistent
   5. Therefore whatever is a part of a whole, in such a way that it cannot exist on its own apart from the whole, is dependent on the whole for its existence
2. The existence of finite things is a part of a whole, in such a way that it cannot exist on its own apart from the whole
   1. Whatever is real is either a whole itself or is part of a whole
   2. The existence of finite things is not the whole finite thing itself
      1. If any existence were a whole thing, it would just be existence itself
      2. The existence of finite things is not existence itself
      3. Therefore, the existence of finite things is not a whole thing
   3. Therefore the existence of finite things is a part of a whole
   4. Every part is either such that it can exist on its own apart from the whole of which it is a part, or cannot
   5. Whatever cannot exist except in combination with another, cannot exist on its own
   6. Existence which is not existence itself cannot exist except in combination with essence
   7. Therefore, existence which is not existence itself cannot exist on its own
   8. Therefore the existence of finite things cannot exist on its own
   9. Therefore the existence of finite things is a part such that it cannot exist apart from the whole of which it is a part
3. Therefore the existence of finite things is non-subsistent

This outline is not as clean as it could be, nor as fully-explicated; but it at least gives a sense for a type of argument for a causal proposition which can be utilized by those with Thomistic sympathies.