The Transactional Interpretation

Mishlove interviewed Ruth Kastner three times, and I've listened to two of the interviews - the one Sciborg posted above and this one:




It seems she is open to panpsychism, but not really to retrocausality on anything but the quantum scale, judging by the exchange starting at about 27 minutes in the "Reality of Possibility" one.

I wish I could understand why the "block universe" should be incompatible with free will. It seems to me that whenever people try to explain that they always end up saying things like "it's already there" or even "it has happened," which is obviously not appropriate when describing a block of space-time extending into the future. The fact that a future observer, or even a hypothetical observer outside time, can know what happened doesn't seem to me any more incompatible with free will than the fact that in the 21st century we know who won the Battle of Hastings in the 11th.

[Laird]

I wish I could understand why the "block universe" should be incompatible with free will. It seems to me that whenever people try to explain that they always end up saying things like "it's already there" or even "it has happened," which is obviously not appropriate when describing a block of space-time extending into the future. The fact that a future observer, or even a hypothetical observer outside time, can know what happened doesn't seem to me any more incompatible with free will than the fact that in the 21st century we know who won the Battle of Hastings in the 11th.

As somebody who used to be a firm believer in the proposition that "Omniscience is incompatible with free will", but has now fully digested the opposing argument, and recognises that it has a degree of cogency, I would say that "It depends on what we mean by 'free'".

That is to say that, on the one hand: sure, in one sense of "freedom", it is reasonable to say that the fact that a hypothetical observer outside of time knows what happened/happens/will-happen does not negate the "freedom" of the "willer" whose will is known. After all, it is not the case that that individual's choice is determined by that which we know about it; on the contrary, it is the case that that individual's choice determines that which we know about it.

But it is also to say that, on the other hand, if at time t0, we know with certainty that an individual will, at some time t1 > t0 make a certain choice C1, then, in some meaningful sense, that individual at t1 is not "free" to make any choice other than C1, and, thus, in some sense, lacks freedom.

So, in my view, it's all about what we mean by "freedom"; which sense(s) we intend...

[Laird]

P.S. Please substitute "if it is certainly the case at t0" for "if at time t0, we know with certainty" if that makes my post clearer for you.

As somebody who used to be a firm believer in the proposition that "Omniscience is incompatible with free will", but has now fully digested the opposing argument, and recognises that it has a degree of cogency, I would say that "It depends on what we mean by 'free'".

That is to say that, on the one hand: sure, in one sense of "freedom", it is reasonable to say that the fact that a hypothetical observer outside of time knows what happened/happens/will-happen does not negate the "freedom" of the "willer" whose will is known. After all, it is not the case that that individual's choice is determined by that which we know about it; on the contrary, it is the case that that individual's choice determines that which we know about it.

But it is also to say that, on the other hand, if at time t0, we know with certainty that an individual will, at some time t1 > t0 make a certain choice C1, then, in some meaningful sense, that individual at t1 is not "free" to make any choice other than C1, and, thus, in some sense, lacks freedom.

So, in my view, it's all about what we mean by "freedom"; which sense(s) we intend...

Yes, I agree. But I don't think the block universe means that at time t0 there is certainty about events at t1. Or does it?

hypothetical observer outside of time

What does it mean to observe outside of time?

[Laird]

Yes, I agree. But I don't think the block universe means that at time t0 there is certainty about events at t1. Or does it?

Yes. It does. At least as I understand it, and as confirmed by this article (emphasis mine):

So with that in mind Cortês suggest we imagine a girl, Alicia, who wants to see the block of spacetime. She steps out of our four-dimensional universe, goes into an extra dimension, and then turns back to look at the block universe.

But if Alicia has stepped out of the block of spacetime, what time is it for Alicia? A consequence of Einstein's unifying space and time is that there are no preferred dimensions; there's nothing special about time. Just as all of space exists in the block, so does all of time. "The importance of this is not so much that there is an extra dimension," says Cortês. "The outrage is more that time is confined in our four-dimensional block." So Alicia lives in a timeless space. And when she looks back at the block universe she sees all of our past and all of our future simultaneously.

A block universe implying that, stepping out of it, we can see all of our past and all of our future simultaneously implies in turn that at every time, t_x, events at every other time (past or future), t_y, are fixed or "certain".

[Laird]

What does it mean to observe outside of time?

See the (series of) article(s) that I linked to in my above post to Chris.

Yes. It does. At least as I understand it, and as confirmed by this article (emphasis mine):


A block universe implying that, stepping out of it, we can see all of our past and all of our future simultaneously implies in turn that at every time, t_x, events at every other time (past or future), t_y, are fixed or "certain".

But it specifically says she is "in a timeless space," so I don't think you can say she has certainty at time t0. I think she is a hypothetical observer outside time.

In answer to Sciborg's question, I would say that observing outside time is really equivalent to observing in time, but after all the events one is observing. If there could be an omniscient historian at the end of time, that would be the same thing, provided s/he was only observing. If s/he were observing and had the ability to modify things, that would get more interesting. But I don't think the block universe allows for that?

[Laird]

But it specifically says she is "in a timeless space," so I don't think you can say she has certainty at time t0.

I hold to be true and am willing to defend the proposition: "If P is true timelessly, then P is true at all times t_n".

I hold to be true and am willing to defend the proposition: "If P is true timelessly, then P is true at all times t_n".

Well, I agree that interpretation of what they mean by a timeless observer would make a block universe deterministic. But if "timeless" means outside time altogether, I don't think it would be.