Is Atheism Logical?

The original version of this article appeared in The Free Mind: The Newsletter and Forum of the University of Minnesota Atheists and Humanists 2(7), May/June 1996. I have changed some of the examples and (I hope) made the article easier to read.

In his brief article “Is Atheism Logical?”, Hank Hanegraaff tries to show that atheism is not rationally justifiable. For the most part, Hanegraaff’s article makes flat assertions without presenting any argument for them.1 One exception to this rule is Hanegraaff’s argument that atheism is illogical, so this particular claim is worth treating in detail.

Here is Hanegraaff’s argument:

Atheism positively affirms that there is no God. But can the atheist be certain of this claim? You see, to know that a transcendent God does not exist would require a perfect knowledge of all things (omniscience). To attain this knowledge you would have to have simultaneous access to all parts of the universe (omnipresence). Therefore, as an atheist, to be certain of this claim you would have to possess Godlike characteristics. Obviously, mankind’s limited nature precludes these special abilities. The atheist’s dogmatic claim is therefore clearly unjustifiable. The atheist is attempting to prove a universal negative. In terms of logic this is called a logical fallacy.

Although Hanegraaff’s argument may at first appear plausible to some believers, it contains numerous errors.

Rational justification does not require certainty

First, Hanegraaff seems to believe that in order for atheism to be rationally justifiable, atheists must be able to be certain that there is no god. But rational justification does not require certainty. For instance, although I cannot be certain that there are no ninjas in my house right now, I am rationally justified in believing this to be so (my life really isn’t that interesting). Most atheists do not claim that atheism is certain, but do claim that there are very good reasons to ground it—reasons good enough to justify acceptance of the proposition that God does not exist.

Many universal negatives actually can be proved.

Second, although atheists do not need to prove a universal negative, there is nothing impossible about doing so. When Hanegraaff asserts the contrary, he probably is thinking about statements like the claim that there are no white ravens, which certainly cannot be proved unless we have inspected every cubic foot of the universe and found no white ravens. However, consider the claim that no round squares exist. That sentence asserts a universal negative, but it can certainly be proved since the concept of a round square is incoherent. A number of atheists believe that the concept of God likewise is incoherent.

Likewise, if the existence of some particular thing entails a state of affairs that we know does not obtain, then we can know for sure that that thing does not exist. For instance, we obviously can be certain that a being who prevents all suffering does not exist, even though this statement expresses a universal negative. Similarly, some atheists believe that the existence of God entails states of affairs that obviously do not obtain (for example, the absence of gratuitous evil). Hence even atheists who claim to be certain that God does not exist are not necessarily committing any kind of fallacy in making that claim.2

I want to stress my original point, though: atheists do not have to believe that the concept of God is incoherent, or that certain existent states of affairs are logically incompatible with the existence of God, in order to be rationally justified in being atheists. If it seems intrinsically improbable that certain states of affairs would obtain in a universe with God, and probable that they would obtain in a universe without God, then there is ample justification to believe that God does not exist.

Absence of evidence sometimes is evidence of absence

Third, Hanegraaff fails to recognize that a lack of evidence for the existence of God in and of itself makes atheism rationally justifiable, simply because atheism introduces fewer kinds of things. If there is no good reason to bring in an extra godly layer behind the way things naturally work, then this is reason enough to discount such a layer, just as one would discount claims that matter curves spacetime only because some pixies use their magic to make it so. Hanegraaff himself surely already reasons this way about everything except his god, since he would otherwise have to suspend judgment about the existence of Allah, Krishna, fairies, 900-foot fire-breathing clowns, and any other entities that could conceivably be hiding in some corner of the universe to which Hanegraaff’s experience does not extend.

All of the above aside, omniscience still would not be needed

Hanegraaff’s fourth error is not a very important one, but it illustrates further how incautious he is in constructing arguments. Hanegraaff asserts that “to know that a transcendent God does not exist would require a perfect knowledge of all things ” (italics added). This clearly is not true; if it were true, it would mean that while a person who knew everything could know that God does not exist, a person who knew everything except for Orel Hershiser’s stats could not, which is absurd.


To conclude, then, Hanegraaff’s argument that atheism rests on a logical fallacy fails on two main counts:

  1. One can prove with certainty that God does not exist if (i) the concept of God is incoherent, or (ii) the existence of God is logically incompatible with other facts about the world.
  2. One can be rationally justified in claiming that God does not exist without being certain that God does not exist. This justification can come from (i) the improbability of God given various facts about the world, or from (ii) the comparative simplicity of atheism given an absence of evidence for the existence of God.

So much for his attempt to demolish atheism with one easy paragraph.


1 For instance, Hanegraaff asserts that “the atheistic world view is unable to provide the necessary preconditions to account for the laws of science, the universal laws of logic, and, of course, absolute moral standards,” but he does not even try to explain why he feels this is the case. Hanegraaff makes unsupported assertions so frequently in his article that it is clear he is only interested in preaching to the choir.

2 (Note added 31 Dec 2005) For an anthology of 33 articles devoted to these kinds of disproofs of the existence of God, consult Martin and Monnier’s (eds.) The Impossibility of God (Amherst: Prometheus, 2003).