This is the weekly Q & A blog post by our Research Professor in Philosophy, Dr. William Lane Craig.
Dear Dr. Craig,
As a former New Atheist and student of philosophy in United Kingdom, I have found your arguments for a creative intelligent mind behind the origin of the universe rather fascinating and compelling. Though, I have several insoluble dilemmas which I wonder if you could unpick and make sense of.
First of all, you invoke the KCA as your initial premise for belief in God (a God who created something rather than nothing). You're argument I believe to be valid, but listening to your debate with Dr. Lawrence Krauss, you said some interesting things which in-turn could provide a problem for the KCA and indeed the argument you use from Leibniz.
Your answer to the question, "Why is there something rather than nothing?", was essentially the KCA, or in other words, God is the explanation for this question.
Dr. Krauss then tried to answer the same question by postulating an eternal multi-verse in which our universe is just one out of a possible infinite amount of universes.
You replied by stating that: multiverse or not, it makes no difference to the argument from Leibniz, one could just as easily ask, "Why is there an eternal multiverse in which our universe is one rather than nothing?". I agree that this makes no difference and the validity of your argument remains in tact.
However, this is my problem. Is God himself not 'something' also? If we can rephrase the question from just 'one universe' (something) to 'an eternal multiverse' (still something) then is it not fair to ask, "Why there is a God rather than nothing? If nothing is the absence of anything (any possible entity with any possible properties), then surely God must also be absent, regardless of whether he is outside the space and time in which one universe or a multiverse could exist.
Professor John Lennox, as I understand it, tries to explain this by just asserting that God does not come from anywhere, and God never began to exist like our universe did. Though, it could be possible for the eternal multiverse to never have had a beginning and was just always there. On what grounds can we distinguish between an eternal God and an eternal multiverse in which our universe is one so that these two questions are not just the same, which they appear to be. An eternal multiverse and an eternal God look more or less synonymous, this would take us no further than Pantheism.
Is God not also bound by the possibility that He himself might have never existed to create a universe (or multiverse) in the first place?
Thank you for you time.
Dr. William Lane Craig’s Response
There seems to be an almost irresistible temptation to conflate the Leibnizian cosmological argument from contingency with the kalām cosmological argument from the beginning of the universe. The inevitable result is confusion. Objections are lodged against the imagined hybrid which do not apply to the unadulterated versions of either argument.
To keep clear on these two arguments, let’s get them on the table before us:
Leibnizian Argument from Contingency
1. Everything that exists has an explanation of its existence (either in the necessity of its own nature or in an external cause).
2. If the universe has an explanation of its existence, that explanation is God.
3. The universe exists.
4. Therefore, the universe has an explanation of its existence.
5. Therefore, the explanation of the universe’s existence is God.
Kalām Cosmological Argument
1. Whatever begins to exist has a cause.
2. The universe began to exist.
3. Therefore, the universe has a cause.
Very typically the confusion that results from conflating these two arguments is thinking that the argument asserts that Everything that exists has a cause, which leads, of course, to the question, “What is God’s cause?” But neither argument makes such an assertion. The kalām cosmological argument asserts only that everything that begins to exist has a cause, and the Leibnizian argument asserts that only things which do not exist by a necessity of their own natures have causes. Both arguments are consistent with the existence of an eternal, uncaused, metaphysically necessary being.
So if you listen to my dialogue with Lawrence Krauss on the question “Why Is There Something rather than Nothing?”, you will see that my answer to the question is entirely about the Leibnizian argument from contingency. It has nothing to do with the kalām cosmological argument (that argument comes up in our dialogue “Is It Reasonable to Believe that God Exists?”). I trust that you can see how inept it is to try to answer Leibniz by appealing to the existence of an eternal multiverse, since the question remains, “Why is there an eternal multiverse rather than nothing?"
Now as you note, God is also something, and so if He exists, He, too, must have an explanation of His existence. Leibniz commits no taxicab fallacy (dismissing the Principle of Sufficient Reason like a cab when one arrives at one’s desired destination). No, on Leibniz’s view, God is no exception to the Principle of Sufficient Reason. The explanation of God’s existence is that He exists by a necessity of His own nature. Leibniz’s argument thus terminates in the existence of a metaphysically necessary being.
So the question, “On what grounds can we distinguish between an eternal God and an eternal multiverse in which our universe is one so that these two questions are not just the same, which they appear to be?” is confused. You’re thinking of the kalām cosmological argument, to which the positing of an eternal multiverse would be a relevant reply. But the existence of an eternal multiverse can be granted with equanimity by Leibniz because it is irrelevant to his argument.
Rather what is relevant is whether the universe (or multiverse) exists by a necessity of its own nature. I don’t know of any contemporary philosopher or scientist who believes such a thing. In my published work you can find arguments against the universe’s existing by a necessity of its own nature. It is the contingency of the universe—eternal or not—that distinguishes it from God, who, as the ultimate being, cannot have a cause.
 Reasonable Faith (Wheaton, Ill.: Crossway, 2008), pp. 108-10.