The Child's Wheel
In Chapter 3, Lewis discusses God's divine goodness. In explaining why our systems of morality are not comparable to God's, he says that they are not entirely different, as black is to white, but it is merely a matter of understanding and gradation: God's morality to our is as a perfect circle to a child's first attempt to draw a wheel. This image is a symbol of the limitations of the human mind; compared to God's knowledge, ours is feeble at best, and our condemnations of his actions as foolish or morally wrong are clearly products of absurdity.
The Baboon
Lewis uses an autobiographical image to describe this point further: when he arrived at university, he likened himself and his appreciation for truth to a baboon's appreciation for classical music. This humorously ridiculous analogy is symbolic of a deeper truth: man does not have the proper order of desires. He should prioritize the transcendental over the immanent, yet he does not do so. This symbol is profoundly relevant to people in the modern era, being too willing to set aside contemplation of God in favor of cheap distractions.
The Artist and his Artifact
In an attempt to describe the nature of God's love, Lewis uses yet another symbolic image: an artist's love for his work of art. He loves it, not necessarily for its perfection, but because of its essence. Of course he wants to smooth it out and make it perfect, but his love is unconditional. The process of making it perfect, however, will certainly be painful for the piece of art, as elements of its fundamental identity are ripped out and replaced. In the end, however, the change is certainly for the better, and all the suffering that came during the transformation will be worth it.
Adam's Sin
As many Christian thinkers do, Lewis often uses Adam's sin as a symbol for the sin of the whole of humanity. The Fall, the event in which Adam and Eve rebelled against God and sinned while in the Garden of Eden, is a typically archetypal story, and many trace the entrance of sin into the world back to that very instant. Lewis, however, sees Adam's sin as a symbol of the sin of mankind, but sin had already entered the created world before that, as Lucifer rebelled against God and descended into Hell as Satan, infiltrating the Garden before Eve had even contemplated taking the fruit.
The Pearl of Great Price
In Matthew 13, Jesus tells a parable about a merchant who discovers a valuable pearl, one whose worth is so great that he sells everything he has in order to buy the pearl. He likens this pearl to the kingdom of heaven, as once one gets a glimpse of heaven, he will do everything to pursue it for the rest of his life. Lewis uses this symbol in Chapter X (Heaven) as a metonym for heaven, saying that we have only experienced the want of heaven, never the thing itself, and we must intentionally pursue it in order to experience its true joys, just like in the case of the pearl.
