Analysis - C.S. Lewis' Argument Regarding Atheism

Here is C.S. Lewis' oft-quoted statement regarding atheism in Mere Christianity, taken from the full text online:

My argument against God was that the universe seemed so cruel and unjust. But how had I got this idea of just and unjust? A man does not call a line crooked unless he has some idea of a straight line. What was I comparing this universe with when I called it unjust? If the whole show was bad and senseless from A to Z, so to speak, why did I, who was supposed to be part of the show, find myself in such violent reaction against it? A man feels wet when he falls into water, because man is not a water animal: a fish would not feel wet. Of course I could have given up my idea of justice by saying it was nothing but a private idea of my own. But if I did that, then my argument against God collapsed too--for the argument depended on saying that the world was really unjust, not simply that it did not happen to please my fancies. Thus in the very act of trying to prove that God did not exist--in other words, that the whole of reality was senseless -I found I was forced to assume that one part of reality--namely my idea of justice--was full of sense. Consequently atheism turns out to be too simple. If the whole universe has no meaning, we should never have found out that it has no meaning: just as, if there were no light in the universe and therefore no creatures with eyes, we should never know it was dark. Dark would be a word without meaning.

It may be represented as an argument against atheism. Strictly speaking, though, it is more of an argument against an argument for atheism - namely an argument that Lewis made before his conversion.

There are essentially four propositions at work here:

1. If God does not exist, then reality is senseless.
2. If there is injustice, then reality is not senseless.
3. If there is injustice, then God does not exist.
4. There is injustice.

As an atheist, Lewis wanted to argue that because there is injustice in the world, therefore God does not exist. But further thought revealed to him that not all of the above four propositions could be true at the same time. For if there is injustice, then reality is not senseless. And so it follows (denying the consequent of the first proposition) that God must exist. But it follows from the third and fourth propositions that God does not exist! And so we have a contradiction.

Lewis felt that the first two propositions must be true, and so he must either give up the third or fourth. Either way, he loses his favorite argument for atheism.

Now this quote, in isolation, hardly ends the philosophical battle: for any determined atheist is free to take issue with one of the above propositions. For example, he might deny the first proposition, in which case it would be up to him to make sense of a universe without God. Or he could deny the fourth proposition, and argue (with the relativists) that there is no ultimate standard of right and wrong.