Theists often use the basic metaphysical principle that something only comes from something as evidence for God’s existence.  We reason that if the universe (something) came into being, then it must have been caused to come into being by something else – it could not have simply materialized out of nothing without a cause because out of nothing, nothing comes.  The something that brought the universe into being must itself be immaterial, spaceless, and eternal, which are some of the basic properties of a theistic being. 

I have heard a few atheists object to this argument by questioning the veracity of the basic metaphysical principle that something can only come from something on the grounds that we have never experienced nothing to know whether or not it is possible for something to come from nothing, and thus we cannot know that it’s impossible for something to come from nothing.  While we may not have any direct experience of something that comes into being from nothing, it does not mean it’s not possible.  Indeed, in the case of the universe it was not only possible, but it actually happened.

There are multiple problems with this line of reasoning.  For starters, the objection assumes that the principle in question is an empirical principle formulated by inductive observations of a large collection of somethings (a posteriori).  Since every something we encounter was caused to exist by a prior something, we conclude that something only comes from something.  It is possible, however, that our experience is limited, and if we encountered a larger collection of somethings we would find at least one example of a something that came into being from nothing.  This characterization of the metaphysical principle misses the boat by a long shot.  It is an a priori metaphysical principle whose truth is wholly independent of our experience.  A mere reflection on the notions of “nothing” and “something” makes it clear that something cannot come from nothing.  Nothing is the absence of any and all things: no matter, no energy, no substance, no potential.  For something to come into being, it has to at least have the potential to do so.  Since nothingness lacks even potentiality, it is not possible for something to come into being from absolutely nothing. 

Then there is the problem of begging the question.  These atheists appear to be reasoning as follows:

(1)   If the metaphysical principle is true, then the universe has a cause and its cause is God
(2)   God does not exist
(3)   Therefore the universe does not have a cause
(4)   Therefore the metaphysical principle is false (i.e. it is not evidence for God’s existence).

The crucial premise here is premise two.  It is presumed from the start that God does not exist, and this presumption is used to invalidate the metaphysical principle, which in turn invalidates the inference to theism from the origin of the universe.  The atheist begs the question because the existence or non-existence of God is what we are trying to determine, and thus the proposition “God does not exist” should not serve as a premise in the argument.  Would the atheist accept the following parallel argument?:

(1)   If the metaphysical principle is true, then the universe has a cause and its cause is God
(2)   God exists
(3)   Therefore the universe has a cause
(4)   Therefore the metaphysical principle is true (i.e. it is evidence for God’s existence).

No.  He would charge us with begging the question, and rightly so.  So why should we think premise two in his argument is true, particularly given the fact that the metaphysical principle constitutes an a priori reason to think God exists (to cause the universe to exist)?  The atheist must do more than merely assert that God does not exist; he must provide evidence in support of this claim. 

If the atheist cannot prove that God does not exist, then he can invalidate the theistic inference from the metaphysical principle by providing some independent reason to think the universe came into being uncaused from nothing.  This is problematic as well.  He can’t appeal to scientific evidence because the methods of science make it impossible to identify uncaused entities, and there are no physics of non-being.  He can’t appeal to logic either because there is no logical reason to think the universe had to come into being uncaused from nothing.  Reason moves us in the opposite direction.  The only reason for thinking the universe came into being from nothing is if one presupposes that God does not exist, which begs the question.

Finally, what if the logic of the atheist’s objection was applied to other matters?  Greg Koukl provides a great example.  What if I said “I exist” and someone asked me how I know that?  I would respond by pointing out that if I didn’t exist, I could not contemplate whether I exist or not.  Since I am contemplating it, I must exist.  What if the person responded to my reasoning by saying, “You have never known what it is like not to exist and thus cannot know whether it is possible to contemplate your existence if you do not exist.  You would have to experience non-existence in order to know that it is impossible to contemplate your own existence while not existing before you can claim that your ability to contemplate your own existence proves that you exist.”  We would rightly find this response to be foolish and obviously flawed.  In the same way we can know that one must exist to contemplate their own existence, we can know that something can only come from something else.  These are obvious rational intuitions that need not, and should not be doubted unless we have overwhelming reasons to do so.