Thursday, October 17, 2013

Abraham Sacrificing Isaac: Not What You Think

By my lights, there is no greater challenge to the threat of Biblical inerrancy than the apparent barbarity of God as portrayed in the Old Testament. One apparent textbook example of this is the famous Bible story in which God orders Abraham to sacrifice his beloved son Isaac in Genesis 22. How could God tell a righteous man to murder his own innocent son? The common perception of the story is that Abraham, convinced by God that he was going to lose his son, prepared the sacrifice. The problem with this perception is that it’s false. Abraham knew he wouldn’t be giving up his son, and so the story of Abraham sacrificing his son isn’t quite as bad as it looks.

The Forgotten Part of the Bible Story



You might say, “Wait, how did Abraham know that he wouldn’t be giving up his son?” Because in the previous chapter God promises Abraham that Isaac would have children (see Genesis 21:12). Abraham knew that if nothing else, God could raise Isaac form the dead. This isn’t just my interpretation of the Bible story; it’s the Bible’s. Check out this oft-neglected Bible passage of the story:
By faith Abraham, when God tested him, offered Isaac as a sacrifice. He who had embraced the promises was about to sacrifice his one and only son, even though God had said to him, “It is through Isaac that your offspring will be reckoned.” Abraham reasoned that God could even raise the dead, and so in a manner of speaking he did receive Isaac back from death.[1]
In light of all this it’s also noteworthy that just before the would-be sacrifice, Abraham tells his servants, “Stay here with the donkey while I and the boy go over there. We will worship and then we will come back to you.”[2] If the Bible story is true, Abraham evidently believed he would be coming back with his son alive, even if he didn’t quite know how that was going work. I think God’s test of Abraham was a test of how well Abraham trusted in to fulfill God’s promise to him.

You might say, “But God was asking Abraham to kill his son, and that’s highly atrocious!” But how good or bad an action is depends on the context, e.g. what results from the action. In our world, rendering someone temporarily unconscious isn’t nearly as bad as killing them because if you kill someone they stay dead and their life is permanently taken from them. But now imagine a scenario I’ll call the “Wake Up World” in which killing someone and temporarily rendering them unconscious are equivalent: if you kill someone, they come back from the dead and wake up like they took a nap. Thus in the context of this world, killing someone isn’t really that bad because it’s basically equivalent to making them take a nap; killing someone would be no worse than temporarily rendering them unconscious.

But then if we are to be consistent thinkers, we must recognize the same logic of the Wake Up World—whereby killing is no worse than rendering someone temporarily unconscious—also holds in the case of Abraham and Isaac whether we like it or not. So while it may seem emotionally repulsive to liken Abraham killing Isaac to Abraham speeding up Isaac’s naptime schedule, because of the unusual context akin to the Wake Up World it’s not all that far off. We can think of God saying something like, “To test your faith in me I’m asking you to place the welfare of your child in my hands in rendering Isaac temporarily unconscious.” Think of it like a trust exercise in which you fall backwards and you trust the person behind you to catch you. No real harm comes because you know there’s someone to catch you, a bit like the way Abraham knew God would catch Isaac.

Conclusion



I suppose the critic could say that even with these factors considered there’s still a problem, but a few things should be noted. First, even if there is a problem, it’s not nearly as big as the common misperception would have us believe, since at worst Abraham believed he would be rendering his son temporarily unconscious. Isaac would take a rather unusual nap and then wake up. Second, at least with respect to what would happen to Isaac, the biggest problem seems to be an emotional one rather than an intellectual one. Intellectually, the logic of the Wake Up World seems solid; clearly in a context like that killing someone is no worse than rendering them temporarily unconscious. Emotionally, it’s harder to accept that once you put in a father and son to instantiate this concept, and I can understand how it would be emotionally difficult to separate the unusual context of the Bible story—where in this case Abraham was basically being asked to speed up little Isaac’s naptime schedule—to the normal context of the everyday world.

In any case, we should all at least get rid of the misperception that Abraham thought he was losing his son, because that’s just not how the Bible story goes.





[1] Hebrews 11:17-19 (NIV)

[2] Genesis 22:5 (NIV)

Sunday, October 6, 2013

The Misleading Krauss? (p. 3)

Krauss and Craig
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Psychology



The psychology of the whole thing is interesting. Believe it or not, I don’t think Krauss was deliberately dishonest, and that’s not just me engaging in the principle of charity. Krauss did after all admit that the universe beginning to exist was likely, and that’s something a lot of atheists aren’t willing to concede. It is for all I know possible that there was a bit of rationalization for not including certain parts of the email that might deliver a false impression (it certainly would have mislead me if I hadn’t been more familiar with Vilenkin’s work), but even if so I don’t think that’s the only factor. Remember this part from Krauss’s Facebook post:
2. we both agree that the edited version does not distort the content or ideas expressed in the original email at all. Those who are claiming otherwise, including apparently Dr. Craig, are mistaken.
It does seem odd that neither Krauss nor Vilenkin seemed to realize how misleading the edited email was. Lest you fear I’ve been hoodwinked by Krauss here, I was able to confirm from Vilenkin himself that this email is genuine. Yet while it’s easy to account for Vilenkin not thinking the email was misleading by suspecting that Vilenkin was not aware of the full context, how to explain this for Krauss?

I think one factor is the failure to understand the context. Krauss was evidently ignorant that Craig’s claim is that “the universe begins to exist” premise is more probable than not, instead mistakenly believing that Craig’s claim was something closer to certainty. Craig has long argued that the scientific evidence makes a cosmic beginning more probable than not, and that the BGV theorem provides a substantial component in the scientific case for the universe beginning to exist. Recall that the edited email contained the following:
Hi Lawrence,

Any theorem is only as good as its assumptions. The BGV theorem says that if the universe is on average expanding along a given worldline, this worldline cannot be infinite to the past.

A possible loophole is that there might be an epoch of contraction prior to the expansion. Models of this sort have been discussed by Aguirre & Gratton and by Carroll & Chen. ……
Because of the context (that Krauss and possibly Vilenkin were ignorant of), one might be given the impression that this loophole defeats the claim that science renders the beginning of the universe more probable than not, when that isn’t quite the case, since the non-edited version said this:
Any theorem is only as good as its assumptions. The BGV theorem says that if the universe is on average expanding along a given worldline, this worldline cannot be infinite to the past.

A possible loophole is that there might be an epoch of contraction prior to the expansion. Models of this sort have been discussed by Aguirre & Gratton and by Carroll & Chen. They had to assume though that the minimum of entropy was reached at the bounce and offered no mechanism to enforce this condition. It seems to me that it is essentially equivalent to a beginning.
Because of the aforementioned context, I think it’s understandable why one might think editing out the “essentially equivalent to a beginning” etc. delivers a false impression. But if instead Craig claimed that the BGV theorem proves the existence of a cosmic beginning with absolute certainty, the omission about what else Vilenkin says about the loophole becomes more understandable.

Still, even this doesn’t quite go all the way in explain why e.g. Krauss left out the “essentially equivalent to a beginning” part, especially when Craig has repeatedly made it clear that he is not claiming that the premises are known with certainty, but rather that they are more plausibly true than false. It seems that some other factor is needed to adequately explain the evidence. But if it’s not deliberate dishonesty, what else could it be?

I suspect it’s old bit of human irrationality known as “wishful thinking.” Humans sometimes believe what they want to be true when they shouldn’t. Krauss clearly has a powerful motive for not wanting the edited email to be misleading (certainly I would if I were in Krauss’s position, believing the KCA to be unsound and yearning to publicly convince others it is unsound), and for wanting Craig’s claim to be something other than “more probable than not” with respect to a cosmic beginning (since that position would much be easier to attack). Krauss probably missed the fact that Craig’s claim about the beginning of the universe is of the “more probable than not” sort, but even though I think Krauss better understands this position of Craig’s, I’m willing to bet that Krauss still doesn’t believe the edited email is misleading even though he’s been shown evidence to the contrary. I myself have faced the temptation to leave out undesirable facts, and it’s easy to rationalize this by saying something like this:
Well, it’s my job to argue my side convincingly, and since I’m not saying anything false, I’m not lying. If some people get a false belief from what I put forth it’s only because they’re jumping to conclusions, and it wouldn’t be my fault that they’re jumping to conclusions.
If you don’t see why Krauss might adopt a similar strand of reasoning, take for example this with the ellipsis points included and the edited out version italicized:
Any theorem is only as good as its assumptions. The BGV theorem says that if the universe is on average expanding along a given worldline, this worldline cannot be infinite to the past. A possible loophole is that there might be an epoch of contraction prior to the expansion. Models of this sort have been discussed by Aguirre & Gratton and by Carroll & Chen. ……They had to assume though that the minimum of entropy was reached at the bounce and offered no mechanism to enforce this condition. It seems to me that it is essentially equivalent to a beginning.
Technically, Krauss isn’t attaching a statement to Vilenkin that Vilenkin didn’t make by editing out the italicized portion. Krauss was correct that there was technical material after the ellipsis. And he didn’t deny that Vilenkin said the models yielded what is essentially equivalent to a beginning—he just didn’t mention it.

When you’re emotionally attached to some view you’re arguing for, it’s tempting to leave out relevant details that are inconvenient for your side, and it’s easy to rationalize these omissions even when those omissions might create a false impression. This is something we should all be careful about. But how to be careful about that? I have two bits of advice.
  1. Ask yourself, “Might this give a false impression if I leave X out?” and if the answer is “Yes,” include it. Regularly asking this sort of question and giving an honest answer even when the honest answer isn’t what you’d like it to be goes a long way.
  2. Instead of being emotionally attached to whatever view you currently adhere to, be emotionally attached to the goal of seeking truth. When it comes to politics for example, I listen to nonpartisan media sources like factcheck.org, and hold my bias towards sources like those because I think they are more likely to give reliable information than partisan media (whether liberal or conservative).[1] So maybe I can’t entirely avoid bias, but I can try to shift my bias closer to the truth, and when you’re biased towards truth, you’re less likely to mislead.

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[1] How does one accept a fact checking source as reliable? Here’s a good earmark: the source viciously assaults all sorts of misleading political statements regardless of whether the misleading statements favor liberal or conservative viewpoints.

Saturday, October 5, 2013

The Misleading Krauss? (p. 2)

Krauss and Craig
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My interaction with Krauss



There’s more to the story too. Craig made a response at Reasonable Faith arguing that Krauss’s use of the edited email was misleading, and Krauss made a post on Facebook that was appears to be a response to Craig’s claim about the use of the edited email being misleading. To quote Krauss’s Facebook post entry:
From me and Alex Vilenkin--sigh--in muted response to some claims that have been posted by some whose buttons have probably been pushed by being wrong:

"In response to the noise regarding the use of an email communication between the two of us in a dialogue with William Lane Craig, there are two relevant points we have decided to make.

1. we both willingly agreed to the request from Dr. Craig to have the full email, which had been edited on the powerpoint slide simply to save time during a 15 minute presentation by Krauss, as there was nothing in the full correspondence that either of us were concerned about sharing.

2. we both agree that the edited version does not distort the content or ideas expressed in the original email at all. Those who are claiming otherwise, including apparently Dr. Craig, are mistaken.

Lawrence Krauss and Alex Vilenkin"
Last week I had a little electronic interaction with Krauss himself. Here was my Facebook post (with the text formatted a bit for neatness).
@Lawrence Krauss

I think you ought to realize why some people might find the edited version of the email potentially misleading; certainly I would have been given a false impression if I hadn’t known a bit of Vilenkin’s background. To see why, let’s consider a concrete example:
Any theorem is only as good as its assumptions. The BGV theorem says that if the universe is on average expanding along a given worldline, this worldline cannot be infinite to the past.

A possible loophole is that there might be an epoch of contraction prior to the expansion. Models of this sort have been discussed by Aguirre & Gratton and by Carroll & Chen. . . . . .
Whether you realize it or not, this sort of thing might give one the impression that the BGV theorem doesn’t provide significant evidence for there being a beginning of the universe due to the loophole mentioned here. But now look at it in context:
Any theorem is only as good as its assumptions. The BGV theorem says that if the universe is on average expanding along a given worldline, this worldline cannot be infinite to the past.

A possible loophole is that there might be an epoch of contraction prior to the expansion. Models of this sort have been discussed by Aguirre & Gratton and by Carroll & Chen. They had to assume though that the minimum of entropy was reached at the bounce and offered no mechanism to enforce this condition. It seems to me that it is essentially equivalent to a beginning.
Look at this way: a person reading the edited email might say to a theist, “See! There’s a loophole here to get around the supposed evidential force the BGV theorem has for a beginning of the universe.” But when one reads the quote in context, a somewhat different impression is given. By leaving the “essentially equivalent to a beginning” etc. part out, the edited email delivers a false impression about the nature of the BGV theorem and the beginning of the universe, even if that wasn’t your intention.

Now consider another example:
. . . Jaume Garriga and I are now exploring a picture of the multiverse where the BGV theorem may not apply. In bubbles of negative vacuum energy, expansion is followed by contraction. . . However, it is conceivable (and many people think likely) that singularities will be resolved in the theory of quantum gravity, so the internal collapse of the bubbles will be followed by an expansion. In this scenario, . . . it is not at all clear that the BGV assumption (expansion on average) will be satisfied.
Whether you realize this or not, this kind of gives the impression that Vilenkin might believe the multiverse avoids the evidential force of the BGV with respect to a beginning of the universe. Think of an atheist looking at this quote and using it against a theist saying, “See! Vilenkin doesn’t think the BGV theorem provides much evidence for a beginning of the universe.” But including the omitted parts would deliver a somewhat different impression:
On the other hand, Jaume Garriga and I are now exploring a picture of the multiverse where the BGV theorem may not apply. In bubbles of negative vacuum energy, expansion is followed by cocntraction, and it is usually assumed that this ends in a big crunch singularity. However, it is conceivable (and many people think likely) that singularities will be resolved in the theory of quantum gravity, so the internal collapse of the bubbles will be followed by an expansion. In this scenario, a typical worldline will go through a succession of expanding and contracting regions, and it is not at all clear that the BGV assumption (expansion on average) will be satisfied. I suspect that the theorem can be extended to this case, maybe with some additional assumptions.
So there are a couple key omissions here: the sort of model which avoids a big crunch singularity is usually assumed to be incorrect, and Vilenkin suspects the theorem can be extended to this case. Omitting all this has at least the potential to deliver a false impression with respect to what Vilenkin believes about the evidential force the BGV theorem has for the beginning of the universe.

It seems to me that William Lane Craig asked some valid questions (http://www.reasonablefaith.org/...):
Why didn’t Krauss read the sentence, “It seems to me that it is essentially equivalent to a beginning”? Because it was too technical? Is this the transparency, honesty, and forthrightness that Krauss extols? (By the way, Vilenkin’s criticism of these models is the same one that Vilenkin makes in his Cambridge paper: far from showing an eternal past, these models actually feature a universe with a common beginning point for two arrows of time.)

And why did Krauss delete Vilenkin’s caveat that the BGV theorem can, in his estimation, be extended to cover the case of an expanding and contracting model such as Garriga and Vilenkin are exploring? And why delete the remark that such a model is usually assumed to be incorrect?
Maybe there are valid answers to these questions, but the fact that these are pretty good questions to ask reveals that you might not realize how potentially misleading these omissions were when it came to the topic of the BGV theorem and the beginning of the universe. Again, maybe this wasn’t your intention, but omitting relevant details like this isn’t recommended if the goal is to prevent giving a false impression.
Krauss responded:
Wade thanks for your note.. however the points I made were, as I explained to Craig at the time: (1) it is possible that we live in a bouncing universe, even if I would suggest current evidence and theory make that less likely than the alternative. (2) BGV rely on extrapolating back to singularity.. quantum gravity could change everything and we don’t have a theory.. therefore at this point anything goes.. all points in Alex’s email as I showed it.. and beyond that, as I explained.. the universe having a beginning or not (especially poorly defined in the case that time arises after the big bang) is irrelevant anyway, and he should stop fixating on it.. Moreover, as you will see, it was one slide out of 15 or so in a 15 min presentation, and the issues regarding entropy are interesting, but not appropriate for a general, non-scientific audience discussion with craig.
Many of the points I brought up he did not address; indeed there was an almost complete lack of engagement with why the quote was potentially misleading (e.g. Krauss did not answer Craig’s question about why “It seems to me that it is essentially equivalent to a beginning” was omitted). His point about the universe having a beginning or not being irrelevant was puzzling as well as clearly false, since the beginning of the universe is a obviously crucial part of Craig’s argument. Krauss doesn’t address the “It seems to me that it is essentially equivalent to a beginning” sentence and instead continues to talk about entropy as if the “It seems to me…” sentence didn’t exist, just as he did with Craig earlier.

At that point I realized it was probably hopeless to convince Krauss that his edited email was potentially misleading, so I gave him some advice on how to better attack the argument. After all, if he agrees with Craig that the “universe begins to exist” premise is more plausible than its denial, it would be better to attack some other part of the argument. It was my modest hope that my advice would help lead to less misleading statements and more substantive objections.

It’s easy to see how some would suspect Krauss of intentionally misleading his audience with the edited email, e.g. leaving out the “essentially equivalent to a beginning” part, but I don’t think that’s what quite happened. But then how to explain what Krauss did?

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The Misleading Lawrence Krauss?

Krauss and Craig
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There’s been a bit of hullabaloo on the internet about whether noted atheist Lawrence Krauss took Alexander Vilenkin out of context in a public discussion with Christian apologist William Lane Craig. I electronically interacted with Krauss about this matter a little. But for those who aren’t aware of the matter, first a bit of background introducing how Krauss (arguably?) mislead people in a big event in Australia.

Brief Background



Something called the kalam cosmological argument (KCA) goes something like this:
  1. Anything that begins to exist has a cause.
  2. The universe begins to exist.
  3. Therefore, it has cause.
Further arguments are given to show that the cause of the universe is (among other things) a transcendent personal cause. If we have adequate grounds for thinking the universe has a transcendent personal cause, this gives at least some evidence for the truth of theism. You can see justification for premise 1 at my Anything that begins to exist has a cause article.

What about the second premise? Craig argues that the scientific evidence currently makes the universe having a beginning more probable than not, and that the Borde-Guth-Vilenkin (BGV) theorem plays a significant role in the scientific case for a cosmic beginning. Why? The BGV theorem says that any universe that has on average been expanding throughout its history cannot have an infinite past but must have a beginning. This would close off a lot of avenues for those who want to avoid a beginning of the universe, for the theorem holds even if our universe is part of a multiverse, the multiverse would also require a beginning if the “has on average been expanding throughout its history” part holds true.

In a nutshell, here’s what happened: Krauss quoted an edited email of Vilenkin that gave some caveats with respect to the efficacy of the Borde-Guth-Vilenkin (BGV) theorem. Theists like William Lane Craig have often used the BGV theorem in arguing for a beginning of the universe, whereas Krauss denoted some of the limits of the theorem in their discussion in Sydney Australia.

Misleading Editing?



You can see and hear Krauss mention the edited email at around 41:23 of the debate:



In the clip above, Krauss says that the theorem doesn’t hold true in the multiverse, but this misleading. Whether it holds true in the multiverse depends on whether the “has on average been expanding throughout its history” condition is met. If the condition is met, then the theorem does hold for the multiverse, and Krauss doesn’t mention this. Krauss also says that the theorem doesn’t work when there’s quantum gravity, which also isn’t necessarily true (more on that later). For those who want to read the edited email:
Hi Lawrence,

Any theorem is only as good as its assumptions. The BGV theorem says that if the universe is on average expanding along a given worldline, this worldline cannot be infinite to the past.

A possible loophole is that there might be an epoch of contraction prior to the expansion. Models of this sort have been discussed by Aguirre & Gratton and by Carroll & Chen. ……

. . . Jaume Garriga and I are now exploring a picture of the multiverse where the BGV theorem may not apply. In bubbles of negative vacuum energy, expansion is followed by contraction... However, it is conceivable (and many people think likely) that singularities will be resolved in the theory of quantum gravity, so the internal collapse of the bubbles will be followed by an expansion. In this scenario, ... it is not at all clear that the BGV assumption (expansion on average) will be satisfied.

...of course there is no such thing as absolute certainty in science, especially in matters like the creation of the universe. Note for example that the BGV theorem uses a classical picture of spacetime. In the regime where gravity becomes essentially quantum, we may not even know the right questions to ask.
Craig wondered what came after the ellipsis of this claim:
A possible loophole is that there might be an epoch of contraction prior to the expansion. Models of this sort have been discussed by Aguirre & Gratton and by Carroll & Chen. ……
At around 50:18 Krauss insinuates that Craig quotes Vilenkin incorrectly. With that in mind, notice the interaction between Krauss and Craig here:



For those who prefer reading a transcript, here’s a key part of what transpired in the segment above (I apologize in advance for not getting the transcript perfect below; I was hampered by the fact that Krauss repeatedly interrupted Craig and the moderator had only limited success in toning this down):
Craig: [Reading the edited email] The BGV theorem says that if the universe is on average expanding along a given worldline, this worldine cannot be extended [apparently realizing he misread it slightly] uh or cannot be infinite to the past.

A possible loophole is that there might be an epoch of contraction prior to the expansion. Models of this sort have been discussed by Aguirre & Gratton and by Carroll & Chen. [Done reading email] Now the thing is Lawrence that in the very paper that I quoted from Alex Vilenkin last April, he shows specifically, by name, that the Aguirre & Gratton model, and the Carroll & Chen model, don’t work. That there—

Krauss: No no, he says that you have to make an assumption about entropy.

Craig: Yes, he—

Krauss: You have to make an assumption about the evolution of entropy at the point of minimum size.

Craig: Those—

Krauss: So you—you have to make an assumption which he would argue that they don’t have any rationale for. That’s not the same as saying that they’re wrong.

Craig: Well, yes it is. I—he—he argues that the—all of the evidence shows that the universe had a beginning and that in this model—

Krauss: I would agree that all the evidence shows—let’s look—let’s accept that fact.

Craig: All rught.

Krauss: All the evidence suggests our universe had a beginning.

Craig: Oh, OK—

Krauss: But we don’t KNOW! That’s what I keep telling you! Knowing and suspecting are two VASTLY different things!

Craig: I—I’m never saying that this is known with certainty. This is a—a mischaracterization on your part. What I argue is that the premise [the universe begins to exist] is more probably true than false. And actually you agree with me on that—

Krauss: Yeah but—

Craig: that the universe began to exist, but I want to focus—

Krauss: Well I say it’s likely that the universe began to exist—

Craig: —on this claim that I’ve somehow misrepresented Vilenkin—

Krauss: Well but the—but the key line is the last one. That the theorem breaks down—

Craig: Wait a minute.

Moderator: Hang on.

Krauss: — at the point it really matters.

Moderator: One at a time.

Craig: Now there’s more here. Because I noticed that at the end of this paragraph where the Carroll-Chen and Aguirre-Gratton models are mentioned that he specifically shows—

Krauss: [my guess is that Krauss might have thought that Craig was about to ask why Krauss omitted what came after the ellipsis] Because it was technical! He said—he talked about the fact that—

Moderator: Lawrence, hang on. Just let, just let him finish.

Craig: That he specifically shows that these models cannot be past eternal, uh and that they involve therefore a beginning of the universe, just like the others. I—

Krauss: You can do the math if you want.

Craig: Now wait—

Krauss: I’ll let you do it.

Craig: Now wait. I couldn’t help notice although it’s [the slide showing the edited email] is down from the screen now that there was a series of ellipses points following the paragraph—

Krauss: Yeah because it was technical! And I thought it was, you know—

Craig: Well I wonder what you deleted from the original letter. Could it—

Krauss: I—I just

Craig: Now wait—

Krauss: I just TOLD you!

Craig: Now wait. Yeah, but you didn’t—

Krauss: I just told you. He says that you assume of entropy at the lowest point for which there is no rationalization in the papers within the context of the model given, and therefore he finds them unpleasant.
A few specific points to notice: Krauss says the entropy thing is something Vilenkin finds “unpleasant.” Also, Krauss actually concedes that the universe likely had a beginning! This is notable (and surprising) since as Craig said the claim is that the “universe begins to exist” premise is more probably true than false.

To sum up a few key points of the above transcript though, Craig wonders what was after the ellipses points here:
Hi Lawrence,

Any theorem is only as good as its assumptions. The BGV theorem says that if the universe is on average expanding along a given worldline, this worldline cannot be infinite to the past.

A possible loophole is that there might be an epoch of contraction prior to the expansion. Models of this sort have been discussed by Aguirre & Gratton and by Carroll & Chen. ……
Craig was also evidently trying to say that Vilenkin says that the models he mentioned don’t work with respect to extending them to an infinite past. Krauss assures Craig that the stuff after ellipses is technical. To be sure, there was some technical stuff after the ellipses, but there was also something else. Here’s a fuller part of the quote, with a key part emphasized by yours truly:
Any theorem is only as good as its assumptions. The BGV theorem says that if the universe is on average expanding along a given worldline, this worldline cannot be infinite to the past. A possible loophole is that there might be an epoch of contraction prior to the expansion. Models of this sort have been discussed by Aguirre & Gratton and by Carroll & Chen. They had to assume though that the minimum of entropy was reached at the bounce and offered no mechanism to enforce this condition. It seems to me that it is essentially equivalent to a beginning.
Perhaps Vilenkin does find the entropy assumption “unpleasant,” but he also says the last emphasized sentence in the quote above that Krauss never mentions. So why did Krauss omit the part about it being essentially equivalent to a beginning? Because it was too technical?

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