- Some events have causes that strictly precede them in time (i.e., the two events are never simultaneous).
- If E causes F, then both E and F exist.
The presentist might make the following move. Let E* be the state of affairs of its being the case that E occurred. Then, the presentist can deny that E causes F, but affirm that E* causes F, and say that that is close enough to do justice to our intuitions.
But it's not close enough as, surely, the cause of F was an event earlier than F, namely E, not an event like E* simultaneous with F. Granted, E might have acted through an intermediate cause, E1, that is simultaneous with F, but E* is not an intermediate cause.
Moreover, if the cause of F is not E but E*, then what did E do? Let's suppose that E is present and F is going to happen. Then E is causing something. What is it causing? The presentist cannot say it's causing F. The presentist can only say it's causing F*, where F* is the state of affairs of its being the case that F will happen. So, the presentist will need to say that E* causes F and E causes F*.
But now consider this: What connection is there between these two complex states of affairs: (A) E* causes F and (B) E causes F*. They clearly are not independent. There must be some connection between them. This connection cannot be causal if presentism holds, because A is strictly earlier than B. This is puzzling. Is there maybe an explanatory relation between them? Is it, perhaps, the case that E* is causing F because E had caused F*, or maybe the other way around? Neither option seems right. But there should be some explanatory relation between them, or else both should be explained by some third thing. I can't think of what that third thing could be. So let's think whether maybe E* is causing F because E had caused F*, at the time of F. Observe that unless F is an intermediate cause between E and F*, which seems absurd, F had better be prior in the order of explanation to the state of affairs of E having caused F* for the reason that F is prior in the order of explanation to the state of affairs of F* having occurred. So it does not seem possible to make E* be causing F because E had caused F*, because F is prior to F*. Could we say that E was causing F* because E* is causing F? But now the past occurrence of a causal relation ends up happening because of a present occurrence of a causal relation. That does not seem right, either.
In any case, where on eternalist views we had one instance of causation, E causing F, the presentist has cut it up into two, an earlier and a later instance of causation. It is now (let's say) true that E* is causing F, but it was earlier true that E was causing F*. But this is weird: we have two instances of causation in place of one. And instead of the relation relating E with F as it should, what we have is one past causal relation from E to F* and a present one from E* to F.