Home › Forums › 2015 International Workshop on Quantum Foundations › Retrocausal theories › Relational Blockworld: Providing a Realist Psi-Epistemic Account of QM › Reply To: Relational Blockworld: Providing a Realist Psi-Epistemic Account of QM
It’s true that this “interventionist account” of causation kind of disappears when you’re no longer talking about subsystems controlled by agents… Some philosophers might even go so far as to say there *no such thing* as objective causation in a full 4D block universe. This would basically fit with what you’re saying, it sounds like (although it’s unclear to me whether you think there is another non-RBW 4D block picture that *would* have some version of causation).
But I’m not quite willing to go that far. In a full 4D block universe, it seems to me that the role of the external agent (who might cause something in a 4D subsystem via the interventionist account) is basically replaced by the cosmological boundary conditions. In the same sense that an agent outside a 4D subsystem might “cause” something in that subsystem, it seems basically equivalent to say that events in a 4D block universe are “caused” by the cosmological boundary conditions. So I don’t think it’s a good idea to throw out the connection between RBW and retrocausation: people might read that as you denying any role of future cosmological boundary conditions as a constraint on what’s happening now. (And you’re not doing that, are you?)