‘Why don't they teach logic at these schools? There are only three possibilities. Either your sister is telling lies, or she is mad, or she is telling the truth. You know she doesn't tell lies and it is obvious that she is not mad. For the moment then and unless any further evidence turns up, we must assume that she is telling the truth.’” (Lewis, 27)
The same way The Professor explains logically how Lucy must be telling the truth, one could apply the same argument to Jesus Christ’s claims to be the Son of God. the argument is best known as: Jesus was either a lunatic, a liar, or Lord. This loosely translates to Jesus Christ was never caught in a lie, he was not mad, so he must have been telling the truth about his heritage. Others argue that this argument is unsound by formal logic because its first premise eliminates other options. William Lane Craig points out in his Reasonable Faith, that Jesus of the Bible could be Legend and thus not the historical Jesus Christ, thus making Lewis’s argument unsound. However, Lewis rebuttaled this argument with his education as a historical scholar by pointing out that Gospels are not “artistic enough to be legends” in an essay recorded in in God in the Dock reinstating the argument as a sound