Sarkus, Thanks for that; it's useful. I'm not sure if Vociferous's objection is the same as yours. I guess we'll find out. One thing, though. If the infinitely-regressive chain of causes is itself uncaused, it does not necessarily follow that an uncaused cause broke the chain at some point. The uncaused cause might refer to the chain as a whole, rather than to any single link in the chain. It doesn't help with the God argument, though, because if we were to assert that God was the uncaused cause of an infinite chain of universes in an eternal multiverse, say, then there's no reason to prefer that assertion over the one that says the entire chain itself is the uncaused cause.