Say that a true proposition is ontologically ungrounded provided that it is not true because of any combination of what things exist, how things that exist exist and what things do not exist. In particular, an ontologically ungrounded proposition lacks a truthmaker.
It would be really nice if one could argue that:
- No contingent ontologically ungrounded proposition has an explanation.
I don't really have a good argument for (1), apart from the fact that it rings true. But, then again, I am no friend of ontologically ungrounded propositions, so my intuitions aren't the best judge here.
However, while (1) is hard to argue for, I think the following is pretty easy to argue for:
- No contingent ontologically ungrounded proposition has a causal explanation.
Perhaps the presentist will say that World War II was causally explained by the humiliation. But when? As I understand it, when World War II started, the humiliation was already gone. Thus, at no time were World War II and the humiliation both present. Hence, at every time we have a causal explanation relation between two propositions at most one of which reports an ontologically grounded fact. But how can there be a causal explanation relation between two propositions one of which is ontologically ungrounded?
I suppose this is a variation of the old causation objection to presentism.