Lewis' Trilemma and the Reductio ad Absurdum

C. S. Lewis made a proof of Christ's divinity using a reductio ad absurdum, which appears in his book Mere Christianity (though he actually first uses the basic argument in a BBC interview in 1943). According to Wikipedia, Lewis was not the first to formulate this proof, but since he's its most famous exponent, we'll call it his.

Lewis sets up what he calls a "trilemma," a decision between three options, to prove that Jesus is divine. Jesus claimed that he was God which means that either he was speaking truthfully or untruthfully, and if untruthfully he either realized he was speaking untruthfully or didn't realize he was speaking untruthfully. This gives us three possibility: Jesus was either a liar, madman or God. Lewis originally formulated this argument to oppose those who think that Jesus is a good moral teacher, but not divine, since his status as good moral teacher would automatically eliminate liar and madman. Nonetheless, to improve the argument, Lewis actually made arguments that Jesus couldn't have been a liar or a madman, mostly resting on the assumption he wouldn't have had so many followers to follow him around and sacrifice their life for him, if he was a liar or a madman.

The first problem with this argument is the claim that he actually did say that he was God or the son of God. Christian Apologists who use this argument go to some length to establish this first point since 1) Jesus never says directly he is God, though he does seem to say it indirectly in a few places and 2) the sources for Jesus' words are both written well after the events of Jesus' life, in a language Jesus didn't speak, and by people who may not have even met him. If Jesus never did say that he was God or the son of God, then it leaves open the possibility that he was none of the three.

But even if we accept this, the argument still has difficulties. A good way to test an argument is to try to see if we can use it to prove things we don't want it to, as Gaunilo did with Anselem's ontological proof. Here, we notice that we can use the argument to prove that anyone making fabulous claims who can persuade people to follow them and sacrifice their life for them, are neither liars nor madmen. Therefore, Mohammed was the last prophet of God, Joseph Smith was told by God to found a new religion and divinely guided in his translation of the Book of Mormon, and L. Ron Hubbard was able to see into our planet's ancient history, and the story of the great massacre by Xenu. In fact, Jim Jones probably sets the record for persuading people to sacrifice themselves, persuading over 900 followers to give up their life in one day. Clearly, these various beliefs are irreconcilable, so Carrol's argument proves too much.

The fundamental problem is that the argues to gives much credit to Jesus' followers. These individuals are self-selecting and followed Jesus around because they genuinely believed his message (which seems to have been primarily focused on preparing ourselves for the immediate immanence of the second coming). As an itinerant preacher Jesus had contact with probably thousands of people, and yet we have no indication that he had more than a handful of followers. In fact, he seems to suggest that sometimes whole towns would complete reject his preaching. On top of that, one of his followers betrayed him, perhaps for the very reason that he began to realize Jesus was either a liar or a madman. Jesus' movement wasn't significant enough to be noticed by any historians until Josephus makes two brief mentions of Jesus in 94 ad, when the Christian movement had already had multiple generation to grow, and that growth was due to the persuasive ability of the subsequent followers, not of Jesus himself. In short, Jesus persuaded probably few people to follow him, and if we were to put the question to all those who had contact with him, then most of them probably did think he was neither a God nor even had the spiritual authority to be followed around. If we simply say, "those who followed him around, because they were willing to believe he was neither a liar nor a madman, were also willing to sacrifice their lives for him; therefore, they must have believed he was neither a liar nor a madman," then we have only made a circular argument.

We might even attack Lewis' first argument. There's no way we could automatically say that a liar or a madman couldn't be a great moral teacher. If a liar, he may have simply used this one noble lie in order to give greater authority to his teachings. And if his madness was limited to merely the status of his own divinity, he may still have been lucid on other critical moral matters, especially if he was simply repeating moral maxims directly from the Tanakh (Old Testament). In short, the Lewis' argument fails in several different ways, and certainly cannot replace faith.