Thanks Ken. Maybe I should clarify my clarification: What I had in mind was something like the ontology I sketch in here:
http://bjps.oxfordjournals.org/content/57/2/359.short
The measurement direction constitutes the retrocausal influence from the measurement back to the source, and the actual spin value constitutes the forward-causal influence…[Read more]

Thanks, that’s helpful.

Thanks, Ken, this is super helpful. I’ll definitely add the unconditional probabilities, as you suggest. And you’re right that I shouldn’t say that there’s NO sense in which preparation and measurement are the time-reverse of each other – I should say that they’re not entirely the time-reverse of each other.

Now on to your main point about inter…[Read more]

This is a very interesting idea. Here are a couple of questions about how it might work:

You write that “it seems natural to assume that the origin of the Born probabilities is the random discontinuous motion of particles”. Certainly some kind of reconciliation of your interpretation of the wave function with the Born rule is required. If a…[Read more]

Thanks for your helpful comments, Robert. I should make it clear that Bell’s view of what the beables are is not the only view, or the best. Spontaneous collapse and Everettian theories I think agree with the consistent histories approach that subspaces of the Hilbert space are the beables.

And you are right that I should clearly distinguish…[Read more]

Good. I guess I don’t see why causality in a block world should (in general) be superfluous (or inconsistent). You can ask “Suppose this measuring device setting had been different — would anything earlier have been different?” If yes, then you’re retrocausal. But what I suspect is that it’s hard to answer this question in RBW because of the…[Read more]

Thanks, Matt, that’s helpful.

About Bell and K&S: You’re right that the theorems apply equally to theories in which the wave function is ontic. I should make that clear. They constrain property ascription in Everett, for example. But Everettians can shrug their shoulders – of course you can’t ascribe pre-measurement properties to systems corresp…[Read more]

OK, good. As long as we’re all clear on the differences between diachronic and synchronic holism, I have no objection! Thanks again for the input.

Aha! Now I get it. Sorry to be so slow!

Yes, that’s nice, thanks for the suggestion. Here’s my only worry. In the regular EPRB case (fig 2), we need a holistic property of the pair (of two points of space on a hyperplane) because Bell’s theorem tells us that you can’t make do with intrinsic properties of the two points alone. But in the…[Read more]

I have a bunch of questions and comments, but let me start with “Is RBW a retrocausal account?” You cite Geroch approvingly saying that nothing changes or moves in the blockworld. But that doesn’t seem right to me. Change/motion only make sense from the perspective of a world-line — the properties of one temporal part of the world-line are…[Read more]

Thanks for the clarification! Some questions: Can I gloss “undirected spacelike link” (in figs 2 and 3) as “holistic property”? If so, then figs 2 and 3 have them, and fig 1 doesn’t. But you say fig 3 “strikes me as also ~holism”. It strikes me as holism!

But maybe you mean that fig 3 is holism and fig 1 isn’t (according to me), and yet (as you…[Read more]

Thanks Mark. I agree that there’s something that smells like holism in retrocausal approaches. But it’s a dynamical something — as you say, it has to do with causal links, and whether they’re directed or undirected. There’s a different kind of holism that’s (arguably) absent in the retrocausal framework, namely property holism. There’s no need…[Read more]