William Lane Craig is a philosopher and theologian, most famous for advocating the Kalam cosmological argument for the existence of God. As far as I can tell, he is fairly well-respected in the theology community; I cited him among other people in my recent paper. He’s also a frequent participants in debates against atheists. These are slightly weird events; everyone says they’re a terrible idea, but everyone seems to willingly participate in them. Personally I think they can be a very useful forum, if done well.
Craig recently debated Lawrence Krauss in an event that got a lot of publicity. You can read Craig’s post-mortem reflections here; in response, Krauss has offered his own thoughts on how things went down, which are posted at Pharyngula. You can watch the whole thing on YouTube, but be warned it’s a long multi-part extravaganza.
As to who won, it’s a mixed bag. Craig is a very polished debater, and has his pitch honed to a fine sheen; every sentence makes a succinct point. On the other hand, many of his sentences are simply false. For example, he argues that the universe can’t be eternal, because infinity is an self-contradictory notion, because “infinity minus infinity” has no correct answer. This is not an unfair paraphrase.
In response, Lawrence was game, but much more impressionistic, with a style more appropriate to a public talk than to a formal debate. It depends on what you’re looking for, of course; he did have the advantage of being right. Craig is sufficiently good at debating that atheists are now advising each other to stay away from him for fear of looking bad — e.g. here and here. I sympathize with the general message — don’t get into something like this unless you know what’s coming and are truly prepared — but not with the final impression, that atheists should just steer clear. We should be good at presenting our arguments, and ready to do so. Craig is wrong about many things, but he’s not an out-and-out crackpot like Hugh Ross or Ken Ham. A good debate could be very interesting and helpful to thoughtful people who haven’t yet made up their minds. Being correct is already a huge advantage; we should be able to make our side clear using the force of reason, like we’re always telling people we do.
The universe is, as far as we can tell, spatially infinite. (If it’s spatially-finite, then its “size” is larger than we can see.)
It will also endure infinitely in the future (will not recollapse).
So, I guess your question is about whether it extends infinitely into the past. The answer is “Possibly yes, possibly no, but it is way beyond our current abilities to definitively decide that question.”
But that is a scientific question, not something decidable by the application of childish syllogisms.
A debate about whether there is sufficient evidence for the existence of god is worse than useless unless both sides first agree on “what is a god?”
If one party says ‘god’ is the creator of the universe. Fine. Then by that definition there is a god since there is a universe. However, if they go on to say that god not only created the universe but also selectively intervenes to change the course of events in ways contrary to the laws of physics, then they have a problem with their neural network. In other words, they claim that god can perform miracles. Like changing the path of a giant meteor such that it won’t smush the Vatican. There is no evidence for miracles. None.
There are many things we still don’t understand completely or can’t prove in exhaustive detail. But there is no evidence for miracles as I define it in the example above. A miracle is not simply an improbable event. Physics allows improbable events. A miracle is an impossible event, i.e., an event not allowed by current law. Like me putting your head in my tub and your torso in the trunk of my car. And three days later I meet you at church bingo! That is a miracle because it defies all current law.
Now if they claim there is a god but “he/she/it” does not intervene in the day to day affairs of the world, then I counter: What is the difference between a god that does not intervene and no god?
Whether or not Craig is well-respected in “the theology community” largely depends on what you mean by “the theology community”. If you mean “the US evangelical protestant theology community”, then perhaps.
I’ve never met a mainline protestant theologian outside the US who think he’s worth a mention. I used to hang around (and talk a lot with) many theologians, and I’d never heard of him until I started reading atheist blogs. These aren’t ultra-liberals, either; we’re talking about people who think Jurgen Moltmann and Wolfhart Pannenberg are brilliant. But if Craig warrants a thought, they seem to think that he’s to theology what Ayn Rand is to philosophy.
Oh, and that’s just the Protestants. Eastern Orthodox and Roman Catholic theologians are usually even more dismissive, if they’ve heard of him at all.
@whoschad
In the most well-established model today, the Big Bang theory, the universe is finite in both time and space, but it is less clear whether it will last infinitely into the future. So I think the point here is mostly to show that Craig’s argument is wrong.
@KWK
It may be helpful to state exactly what your argument is. I will paraphrase it to the best of my understanding, please point out if this is not what you meant. Even in an infinite universe, there is still a finite amount of time between any two fixed events. So to say there is infinite time before an event, you need to go back to a “beginning” of the universe, which doesn’t exist (this is the whole point of assuming the universe being infinite in time).
So the statement you are claiming is probably:
If in a hypothetical universe, there is an event B such that for any length T of time interval, there exists an event A such that the time interval between A and B is greater than T (that is, there exists events arbitrarily far in the past), then such an universe is logically inconsistent.
However, that statement is clearly false. When Sean said that it is easy to construct a consistent universe with infinite time, I suppose he has something like this in mind: consider an universe with three dimensional Euclidean space. There is a set (can be either finite or infinite) of “particles” having certain positions and velocities at time t=0. They move linearly at constant speed at all times, so their location at all times are determined. This, then, gives a hypothetical universe, clearly consistent since it is based on a simple mathematical model.
Granted, this is not a very interesting universe, certainly very unlike ours. However, we should be able to construct more complicated models, while preserving the property of lasting infinitely in time. If your argument is to work, you need to establish something like:
If a hypothetical universe is “interesting” / “similar to ours”, and has the property given above, then it is logically inconsistent.
First, you need to define “interesting” or “similar to ours”, then use this condition to show an inconsistency. You have to use some condition since you don’t want your argument to work on the simple universes constructed above.
@Kevin and others
I have to agree that live debates are not very useful in showing relative strength of arguments, since a lot depends on the skill of debaters. This is especially important here since most of the debaters on the atheists side have professions very different from debating. I think doing debates in writing, giving everyone ample amount of time to think, would be much more useful. Unfortunately it will also have very limited effect considering that an average people today isn’t going to spend hours reading philosophical arguments 🙂
@KWK:
No, you haven’t demonstrated any logical impossibility, you’ve merely re(/mis)stated the premise and called it logically impossible. There is no “traversing” being done – the universe includes time in it. To say the universe goes back infinitely far back in time is exactly like saying it can extend infinitely in spatial directions – would you argue that spatial infinity is impossible because nothing can “traverse” an infinite distance (in a finite time, at least). Never mind that for photons exactly zero time has passed since the Big Bang (or any event).
Also, if there isn’t a true infinity at the Big Bang singularity, then there isn’t a true origin of time either.
The full debate is uploaded here; http://www.youtube.com/view_play_list?p=F07912BD59617C72
Introduction start in part 2, 2:12 seconds into the video.
KWK,
Could you please define exactly, what you mean by `traversing`. The term confuses me.
Surely the thing to do is to GET ALAN GUTH OR ALEX VILENKIN TO DEBATE WLC.I havent read anythting by Borde but I am confident neither of these two (that WLC quotes again and again again) agree with WLC having read their books. Vilenkin is very explicit that their therom does not support the case for theism yet WLC conveniently ignores this quote.
@KWK
YEs if you quantize space time then you can avoid infinities but the conseqwuence of that can be avoiding a begining of time:
for example see Abhay Ashtekar:
http://iopscience.iop.org/1742-6596/189/1/012003/pdf/1742-6596_189_1_012003.pdf
“However, because gravity is geometry in general relativity, when the gravitational field becomes singular, the continuum tares and the space-time itself ends. There is no more an arena for other fields to live in. All of physics, as we know it, comes to an abrupt halt…When faced with deep quandaries, one has to carefully analyze the reasoning that led to the impasse. Typically the reasoning is flawed, possibly for subtle reasons. In the present case the culprit is the premise that general relativity —with its representation of space-time as a smooth continuum— provides an accurate description of Nature arbitrarily close to the singularity…The situation is very different with quantum evolution. As the density and curvature enter the Planck scale quantum geometry effects become dominant creating an effective repulsive force which rises very quickly, overwhelms the classical gravitational attraction, and causes a bounce thereby resolving the the big bang singularity.”
So a qauntized solution may remove the infinites at the classical singualrity but it can also remove the begnining of time in the process.
Thast why I think WLC argument is a contradiction. If you want to keep a classical picture, yes you get a beginnning of time , but you also get a bunch of infnite vlaues = something WLC insists is impossible. If you use a quantum approach you may get rid of the infnities but then the beginning of time looks a lot more doubtful.
I have to pile on. Zeno’s paradoxes are precisely on point. The prospect of infinity is present in any interval, no matter how small. There is a one to one relationship between a single step and an infinite distance, and between a second and eternity.
Taking a step refutes Zeno, because the infinite sequence of intervening points is not an incomprehensible horror but a necessary consequence of treating the process arithmetically.
A debate doesn’t figure out who is right and who is wrong, it simply finds out who is the better debater.
It’s fun, sometimes insightful, but epistemologically useless.
“Does anyone ever discuss Godel’s incompleteness theorem in these theological debates? It seems to me this could be the best point theists have in their favor — if there are things which are true but can never be proven, isn’t that in a sense a logical justification for religious faith and a fatal blow to scientific rationalism?”
Just because there are some things which are true but cannot be proven to be true doesn’t mean that an arbitrary claim without proof is true.
A serious question: Gödel’s theorem relies on constructing something like “a consistent system will not be able to prove that this statement is true”. Are there any other “obviously true” statements which cannot be proven which don’t rely on this special construction?
Gödel’s theorem gets a lot of press mainly because people think it gives them some sort of superiority: they can see that the statement is true, even if a powerful computer can’t, and believe that this makes them superior to a machine. But what is the difference between this and “Roger Penrose will never have the thought that this statement is true, although I can”? Does this make me a better thinker than Roger Penrose? (I use “never have the thought” to avoid the red herring that Roger can glimpse the truth but doesn’t want to utter it etc. Also, if we base our judgment of machines on what they display, but of people on what they think, then there is the danger of assuming that that which we wish to prove (machines can’t really think) is true.)
“For example, he argues that the universe can’t be eternal, because infinity is an self-contradictory notion”
1. Dr. Craig’s point was that quantitative infinites exist as an idea–but that it’s implausible that they exist in the actual world. For example, what or who would stop somebody from taking or adding coins to an infinite number of coins; and if you’re allowed to add coins to an infinite number of coins, then wouldn’t that prove that there wasn’t already an infinite number of coins? For a better example of the logical incoherence of actual quantitative infinites, please see Hilbert’s paradox of the Grand Hotel.
2. There’s also no empirical evidence for the existence of actual quantitative infinites.
3. As for the universe itself, current scientific evidence seems to suggest that the universe is past-finite and not past-infinite. Feel free to correct me if I’m wrong.
Regardless, given your responses, I can see why you wouldn’t want to debate Dr. Craig.
Matt,
I don`t think that actual infinities are logically incoherent. The problem you suspect exists comes from a confusion about the nature of subtraction. If we remove all even numbered people from the hotel, we simply have removed infinitely many people, and since we have removed a specified set, we know that there are infinitely many left. However if we don`t specify which infinite set we remove we do not know how many people are left. These are the facts about the matter.
Now you seem to interpret this in the following way:
A: If I remove a subset U from a set X this corresponds to an arithmetic operation, such that the cardinality of the new set X-U is wholly determined by the cardinality of U and X.
B:If U and X are infinite, A is not the case. Hence X must be finite.
However people who use this line of reasoning, give no justification for A. So all that Hilberts Hotel proves, is that if actual infinites exist, A is not the case.
Perhaps Prof. Krauss should have followed the late Stephen Jay Goulds’ advice to Richard Dawkins then the latter asked for his advice relative to debating creationists. Goulds’ response was, “Don’t do it!” The reason is that creationists engage in what is known as the Gish gallop. However, if scientists like Prof. Krauss insist on engaging in such activities anyway, he should consider the example of Brown biology professor Ken Miller when he was inveigled by his students into debating creationist Henry Morris.
Prof. Miller prepared for the debate by reading everything he could find that Miller had ever written and studying any videos of previous presentations by Miller that he could find on the subject of evolution. In this way, he knew exactly what Miller was going to say and he was able to prepare cogent talking points to refute the latter. In this way, he was fully prepared to counter the Gish gallop with a Miller gallop of his own, refuting anything that Miller would say. This is what Prof. Krauss should have done prior to engaging in a debate with Mr. Craig. His failure to do so allowed Mr. Craig to successfully engage in a Gish gallop. I would respectfully suggest to Prof. Krauss or anyone else who is tempted to debate creationists that they either follow Goulds’ advice or Millers’ example.
Re Matt @ #37
Here’s an example of the notion infinity – infinity making physical sense. In quantum electrodynamics, when computing the anomalous magnetic moment of the electron, mu, one is faced with divergent integral expressions. In particular, the expression I – m, where I is a logarithmically divergent integral expression and m is the mass of the electron, occurs. This is resolved by redefining m as m(0), the “bare” mass of the electron, setting it equal to infinity and setting the resulting expression I – m(0) equal to -m. This, of course, is mathematically preposterous; however, this procedure results in a computation that agrees with the observed value of mu to 10 significant digits, rather better than the estimate for pi given by scriptures which is accurate to 1 significant digit.
I’m amazed that Craig is still making that stupid infinity minus infinity argument. I’m also amazed that no one ever calls him on an outright lie: that “mathematicians agree” there can be no actual infinity. The truth is almost the exact opposite: mathematicians agree there is no LOGICAL problem with infinities. Hilbert’s hotel situations are counterintuitive, but they are NOT contradictory, so they don’t disprove anything.
Correct me if I’m wrong, but it appears the Carroll/Barnes exchange above in the comments to this blog has established that (1) Dr. Krauss was wrong in his debate with Craig regarding inflation explaining the low-entropy of the universe and (2) that both Dr. Krauss and Dr. Carroll were wrong and Dr. Craig was right that while events can be potentially infinite into the future, an actual number of events cannot be infinite into the past (because of the Hilbert’s Hotel effect–see http://www.woodford.redbridge.sch.uk/rs/year10-11/hilberthotel.html). That is quite remarkable, but demonstrates the value of blog comments.
You’re wrong. The Hilbert Hotel says nothing at all about whether events can be infinite toward the past. This is not something considered controversial among sensible people.
Sean: “You’re wrong. The Hilbert Hotel says nothing at all about whether events can be infinite toward the past. This is not something considered controversial among sensible people.”
Well, it has been a major point of controversy in the philosophical literature over the last 30 years (see sources gathered here: http://commonsenseatheism.com/?p=1637 Major figures in the field–theist and atheist–such as Sobel, Oppy, Morriston, Quentin Smith, etc. have grappled with it). But I suppose if you believe that all of those who have contributed to the literature of that controversy are “not sensible,” you are correct. That seems far-fetched to me.
To athanasius @41
Actually, if you read Barnes last comment (#14), he also agreed that Craig has not demonstrated any contradiction. If you have time please also read some of the later comments about the possibility of infinite universe and about the Hilbert hotel paradox.
To randommuser:
I don’t read Barnes’ last comment the same way; of course Craig has not demonstrated that the mathematical CONCEPT of infinity is contradictory under the rules of transfinite arithmetic–Craig agrees that it is not. But isn’t Barnes citing Ellis and Stoeger in support of Craig’s position that “an infinite is no where to be found in REALITY” (only as potentiality)? Thus, the series of all events can extend toward a potential infinite in the future, but not into the past, since you would then have an actually infinite number of events–which under Hilbert’s principles is “no where to be found in reality”? If not, perhaps Prof. Barnes can post again to clear it up.
How exactly is William Lane Craig not a crackpot? Krauss incorrectly assumed that Craig accepts evolution, but he doesn’t. Go watch his debate with Shelly Kagan in which Shelly Kagan performed quite well. I think its pretty clear in that debate that he doesn’t think that humans evolved from primates. I don’t know whether debating him is a good idea or not, but it seems like Krauss should have known this about him before he agreed to a debate.
Just for general information, here is a quote that I think sums up nicely why there just simply can’t be a God (or any other similar explanation for things):
“I don’t believe in the supernatural. My principal negative reason is that there is an infinity of mutually inconsistent accounts of supernatural entities, between which reason cannot distinguish. Were I to accept the offer of one which, as it were, knocked at my door offering an underlying meaning in return for my agreeing to suspend my critical faculties, I should have no decent reply to the next one that knocked and asked ‘Why did you not choose me?’
My principal positive reason is that, for various reasons (about which I am writing a book, The Beginning of Infinity), I have come to the conclusion that the world is fundamentally comprehensible — but in a way that rules out the possibility that any ultimate explanation can be discovered. For the latter would necessarily be in terms of entities and attributes which themselves cannot be explained. I expect every true answer to create not closure, but a better question. To seek a final answer is to hope that everything beyond that is incomprehensible. And since that move is always available to shore up any false theory, it must be a mistake.”
— David Deutsch
By the way, the referenced book has just come out. I’m hoping it will be at least as good as yours Sean 😉
This reminds me of a quote from Stephen Henry Roberts:
“I contend that we are both atheists. I just believe in one fewer god than you do. When you understand why you dismiss all the other possible gods, you will understand why I dismiss yours.”
@ 47 Kevin,
An even more brief summation of this negative reason!! Thanks for that.
The entire debate can be watched at http://mckimmon.online.ncsu.edu/online/Viewer/?peid=c71f72ecead9438faf30bb39b4b1c3051d (note: the audio is not that great).