So I have never, ever, ever been able to grasp fully any explanation in any textbook of the difference between cum temporal and cum circumstantial, because the examples they give always seem to contradict the explanations, and I'm wondering whether there's a clearer heuristic than just "the time at which something happens" vs. "the circumstances in which something happens," because a lot of the time I think things should be circumstantial that are actually temporal.
The following rules have been suggested to me or occurred to me, but they always seem to overdetermine or underdetermine:
- In cum temporal, the two clauses have no logical connection with each other. This gets wrong things like Cum Romae estis, agite sicut Romani, which I remember being used as an example of cum temporal in a text. If the people addressed weren't in Rome, the reason to advise them to act like the Romans would no longer exist and therefore there would be no need to say the main clause.
- Cum circumstantial is always susceptible of translation of "since" or "because." But then you get the example Caesar cum loqueretur, ab inimics interfectus est. He wasn't killed because he was speaking; he was killed because he was destroying the Republic.
Any thoughts on a better heuristic?