Non-natural facts explain

Consider this thesis:

1. Only natural facts explain contingent truths.

(So if there are non-natural facts, they are explanatorily epiphenomenal.) I will argue that (1) is false.

For:

2. Only facts knowable by the scientific method are natural facts.
3. The non-existence of immaterial beings that do not interact with the physical world is not knowable by the scientific method.

Now, consider the coherent but false theory that there are two generations of highly intelligent supernatural mathematicians, the first of which are called the "Great Ones" and the second of which are called the "Daughters of the Great Ones", and that they do not interact with the physical world. Then:

4. It is a contingent fact that the Daughters of the Great Ones don't exist.
5. That the Daughters of the Great Ones don't exist is explained by the fact that the Great Ones don't exist.
6. That the Great Ones don't exist is not knowable by the scientific method.

And so:

7. That the Great Ones don't exist is a non-natural fact that explains the contingent fact that the Daughters of the Great Ones don't exist.
8. Therefore, at least one non-natural fact explains a contingent truth.

And this contradicts (1). So, (1) is false. (And if negative states of affairs can be causes, then maybe we can even say that the non-existence of the Great Ones causes the non-existence of their Daughters.)