Four arguments that there must be concrete entities

An entity is concrete provided that it possibly causes something. I claim that it is necessary that there is at least one concrete entity.

Argument A:

1. The causal theory of possibility is true.
2. So, necessarily there is at least one concrete entity.

Argument B:

3. Necessarily, if there is time (respectively: space, spacetime, laws), there are concreta.
4. Necessarily, there is time (respectively: space, spacetime, laws).
5. So, etc.

Argument C:

6. Every possible fundamental fact can be reasonably believed (respectively: known).
7. Nobody can reasonably believe (respectively: know) there are no concreta.
8. Necessarily, if there are no concreta, then that there are no concreta is a fundamental fact.
9. So, etc.

Argument D:

10. Necessarily, if there is nothing concrete, the only fundamental contingent fact is that there is nothing concrete.
11. Necessarily, some fundamental contingent fact has a potential explanation.
12. Necessarily, that there is nothing concrete has no potential explanation.
13. So, etc.

And since, plausibly (though controversially),

14. If it necessary that there is a concrete entity, there is a necessary concrete being,

it follows that there is a necessary concrete being. And this some call God. :-)

An Aristotelian argument from a necessary being to a necessary concrete being

Suppose that none of the participants in World War II had ever existed. Then it would have been impossible for World War II to occur. Why? Because World War II's existence is solely grounded in the existence, activities, properties and relations of the participants, and

1. If an entity x's existence is solely grounded in the existence, activities, properties and/or relations of the Fs, then it is impossible for x to exist without at least one of the Fs existing.

Now add this Aristotelian axiom:

2. If x is abstract, then x's existence is solely grounded in the existence, activities, properties and/or relations of concreta.

Finally, add this:

3. Every being is either concrete or abstract.
4. There exists a necessary being.
5. There is a world where no one of the contingent concrete beings of our world exists.

One might try to give the number three as an example of a necessary being to support (4).

Now, let N be the necessary being of (4). If N is essentially concrete, we get to conclude that there is a concrete necessary being. If N is essentially abstract, then N is grounded in the existence, activities, properties and/or relations of concreta. If some concreta are necessary, we conclude that there is a concrete necessary being. So suppose all concreta are contingent. Then the beings that N is grounded in don't exist at the world mentioned in (5), which violates the conjunction of (1), (2) and the necessity and abstractness of N. So, no matter what, it follows from (1)-(5) that:

6. There is a necessary concrete being.