Arthur: Causality, at least in the classical sense that aristotle would have understood, formal causes, et cetera, is a strictly microscopic phenomenon. At higher levels, we're throwing away information, ok? That's what emergence is all about. There's different microstates that look the same as far as macro states are concerned. Therefore it is often the case that the immersion theory is not deterministic. And there is an arrow of time, ok? So what i would say is there is no reason to ever use words like causality at the micro level.