My response is going to be: "Show me one." Until you show me one, you cannot accuse me of being close-minded because I don't want to consider or acknowledge the existence of unicorns. I'll consider it; but before I'll acknowledge it, you have to come up with a positive argument.
First Argument
About this origin of the universe thing: Dr. Craig said that the universe has a cause, and it has a beginning. As far as I know, that is true (and I am qualifying this because astronomers and cosmologists do change their mind quite often, and things have changed in the last 20 or 30 years, so I wouldn't bet my life on these things). But let us assume that in fact the universe had a beginning and in fact the universe had to have a cause of some sort. Well, that does not imply by any means that that cause was what we refer commonly to as God. It only means that there was some kind of cause that we really don't know much about. It doesn't imply by any stretch of the imagination that that cause was conscious, that it had supernatural powers, that it has omnipresence, omniscience, and all the other "omnis" that you want. The two things simply don't follow. It only means that there is a cause, O.K.? Dr. Craig said that therefore that implies that there is a personal agent. And once again I'm asking, "Dr. Craig, where does this agent come from?" Why does he think it was personal as opposed to impersonal? After all, we might not be that far from each other because scientists do agree that there must have been a cause and that cause probably was impersonal. It's just a matter of defining what you mean by "cause."
Second Argument
Let's go back to the complexity of the universe and the balance of the initial conditions. As I said before, it's really hard to estimate probabilities. These estimates that Dr. Craig referred to as the Anthropic Principle are really, really wild. If you ask a lot of physicists, as I have done, they'll tell you that those calculations really have no basis whatsoever. We simply don't know. We don't know enough. It's very easy to pull out of the hat any kind of number that shows that something is highly improbable. I don't know if you have noticed, but Dr. Craig keeps presenting these probabilistic arguments--for example, for the probability of the evolution of humans. And the people that he cites are either physicists or chemists, not biologists. Don't you find that peculiar? I mean, the problem there is this: I don't feel qualified as an evolutionary biologist to go into a physicist's lab and tell him how the atom works. That's not my job; that's the physicists' job. I find it peculiar, on the other hand, that physicists and chemists have no problem whatever getting into the field of biology, counting out their numbers out of their hats, and not furnishing any good reason for doing that. It is their prerogative, of course, to do that--inquiries are open to everybody--, but you have to have solid reasoning to do that.
By the way, I'd like to mention that you should never believe something just because somebody says it, no matter how important or famous that person is. Case in point: Dr. Craig has cited a couple of times Fred Hoyle. Fred Hoyle is a very well- respected and known British astronomer. He came up with quite a few bizarre ideas throughout his career. In fact, he came up with so many bizarre ideas in his career that the British Astronomical Association gave him, and only to him, a medal for the highest number of wrong theories proposed in a career. Notice that that is an important fact because Fred Hoyle, for example, was one of the people that opposed the Big Bang theory of the origin of the universe, and the British Astronomical Association gave Fred Hoyle this medal because we do have in fact a lot of people working on the Big Bang theory, and we have learned so much about the Big Bang theory in part because so many people were upset with Hoyle when he proposed his theory. So you know, wrong proposals do have very good and positive results sometimes. That doesn't mean you should believe them.
Third Argument
Let's go back to this thing of objective morality. I think that there's a little bit of twisting and turning around here with terms. Again, it's not a matter of "Is there out there an objective morality?" We know that there isn't. There are some components of your own morality that are not shared by other human beings. So either you are pretentious enough to think that your morality for whatever reason is the only correct one, or everybody else in the world is wrong.
I think that that is pretentious. Of course there are some universals that all human beings share. Just today, for example, I told my students in a biology class that there are some things that human beings and society would never approve because of the way human societies are built. One, of course, is homicide; another one, of course, is rape. However, what we call homicide or rape or, in fact, even infanticide is very, very common among different types of animals. Lions, for example, commit infanticide on a regular basis because they want to make sure that the little offspring that is being raised by the lioness is their own and not someone else's. Now, are these kinds of acts to be condoned? I don't even know what that means because the lion doesn't understand what morality is, that's for sure.
Morality is an invention of human beings. It's a very good invention. I'm not suggesting we should abandon morality. I'm not suggesting, more to the point, that we should abandon ethics. Ethics is a perfectly valid way of thinking about things. We can all agree as a society that there are things that are wrong and things that are good. We can act on them, and we can enforce those things, but there is no higher power or no higher reason to tell us that this is right or this is wrong. Unfortunately, we are on our own; that's my humble opinion. I would really like for somebody to come down from the sky and tell me what is right and what is wrong. My life would be much, much easier. Unfortunately, that doesn't happen.
Fourth Argument
How about these historical facts of Jesus that somehow Christianity explains? Well, there are a few things that I would like to bring out on that. That, obviously, is a little bit on the side of the scientific arguments. It is really difficult to do a science of history. In some cases you can do it, but certainly with a unique historical event it is difficult. That's one of the limitations of science. Science, by the way, has limitations. I hope that that will be clear from tonight' talk. I'm not advocating science as a substitute for an omnipowerful God. But there are a few things that we can surmise from what we know about the origin of mythologies and the origin of religion in general.
For one thing, according to Roman documents of the time, Jesus was just one among a lot of people that told people that they were prophets and were doing miracles. There were a bunch of them. He was just one of many. He probably was a particularly gifted one, and that's why his particular brand of religion eventually succeeded. But there were many; so why think that that particular one was special? Just because by historical accident it happened to be one of the most successful? So was Mohammed's, Islam is incredibly successful; in fact, it is the second most popular religion in the world. Well, are all the Muslims wrong and off track just because they happen to believe in the wrong prophet? On what basis can you make that judgment?
Now what about these miracles? We can find a bunch of people that claimed to make miracles, that claimed to be prophets, throughout history, including today. I think you can get the address and send e-mail to people who claim to be prophets and miracle makers. Would you believe them? Well, I don't--not without seeing something really in person. Now, of course, people do claim to have seen miracles in person, but then again people also claim to have been abducted by aliens or to have seen fairies around, or gnomes, or whatever else you want. Now, by the way, even though I don't believe in UFOs and alien abductions, I think that those are much more credible than miracles. For one thing because a race of aliens coming in on Earth and interfering with our personal affairs--although you might ask, "Why would they want to do that, why would they want to travel out this way just to abduct a couple of people from the countryside of Iowa?"--this puzzlement aside, they don't violate any physical laws that I know. It may have taken them a long time to travel at subluminal speed without violating the theory of relativity to get to this planet, but they could have done it; there is no question about it. They are not violating any physical laws. Miracles do. Now there is nothing wrong with that either, and you can still believe in miracles. The problem is, you can't pick and chose; you can't think that naturalism in absence of miracles works most of the time and then when it is convenient for you a miracle happens. Because the most likely explanation for that is that something happened for which you simply don't have any other idea of what it was, and I think it's much more humble and less pretentious, if you want to use this term, to just say, "I don't know." There's nothing wrong with that. "I don't know" is much better than saying, "Well, I'm going to make up a whole story about what has happened, and this is the result of a higher being, of which I know nothing and I can know nothing."
Argument from Imperfections
Dr. Craig finally pointed out that it is pretensions of atheists, or non-theists, as I said I prefer to be called, to guess the mind of God. Of course, it is pretentious, but it's a trick. Here is the trick. I can say I'm not pretentious enough to know the mind of God, but I still need an explanation of why God is doing things one way or the other. To simply recoil into "Well, he did it because he felt like it" or "He knows better" again is no explanation. It is not satisfying from an intellectual point of view. It may very well be true. After all, probably mice in laboratories all over the world do wonder what the heck are we doing with them, making them go round and round in circles, and testing their intelligence. They probably do that, and they certainly don't have the brain to understand what's going on. At least that's what we think. But you have to ask the question, and if the answer is, "I don't know," then I'm afraid that the theistic position is in no better shape than it was when we started.