Van Tillians also stress the importance of reckoning with "the noetic effects of sin" (that is, the effects of sin on the mind), which, they maintain, corrupt man's ability to understand God, the world, and himself aright. In their view, as a fallen creature, man does know the truth in each of these areas, but he seeks to find a different interpretation—one in which, as C. S. Lewis said, he is "on the bench" and God is "in the dock." The primary job of the apologist is, therefore, simply to confront the unbeliever with the fact that, while he is verbally denying the truth, he is nonetheless practically behaving in accord with it. Van Til illustrated this alleged inconsistency as a child, elevated on the father's knee, reaching up to slap his face, and Bahnsen used the analogy of a man breathing out air to make the argument that air doesn't exist.