A Despot, Not a Lover
"Those Divine demands which sound to our natural ears most like those of a despot and least like those of a lover, in fact marshall us where we should want to go if we knew what we wanted." - p. 23 (III: Divine Goodness)
In this dual simile, Lewis is making a comment about the way we perceive God's commands and the ways this perception differs from reality. We see him as a despot: a merciless ruler who orders you to do things you don't want to do for his own benefit. In reality, however, he is more like a lover: the things he asks us to do are truly for our own benefits, shaping us to be the most perfect version of ourselves, despite our hasty assumptions to the contrary.
The Abolition of Noses
"A God who did not regard this with unappeasable distaste would not be a good being. We cannot even wish for such a God — it is like wishing that every nose in the universe were abolished, that smell of hay or roses or the sea should never again delight any creature, because our own breath happens to stink." - p. 33 (IV: Human Wickedness)
This humourous simile comes in the middle of a discussion about God's justice and goodness. Since He is ultimately good, he can't stand the presence of evil; he loves us unconditionally, but he desires that we become sanctified in order to become whole and complete. Sin is an extraordinary irritant to him, and we should desire that it stays as such - a God whose goodness is weak enough to tolerate the presence of evil is not a God worth worshiping. To illustrate this point, Lewis uses the analogy of wishing for the abolition of noses because our breath stinks, equating this to wishing that God would abolish pain because we don't find it comfortable.
The Bad Tennis Player
"We imply, and often believe, that habitual vices are exceptional single acts, and make the opposite mistake about our virtues — like the bad tennis player who calls his normal form his “bad days” and mistakes his rare successes for his normal." - p. 34 (IV: Human Wickedness)
In this chapter, Lewis is addressing the inherent wickedness of humans. This particular section is part of his argument that humans don't even know about their own essential sinfulness. The tendency is to write off continually indulged vices as one-off mistakes, exceptions to the rule, while seeing the exhibition of virtues as our default setting, despite the fact that it is in fact the opposite. The "bad tennis player" mistaking "his rare successes for the normal" is a funny yet profoundly affecting insight into human nature.
Vermin
"Yes: we behave like vermin, but then that is because we are vermin." - p. 52 (V: The Fall of Man)
This is the excuse Lewis justifiably puts in the mouths of humans, who are by nature sinful and who act in accordance with natural fleshly desires. By using such a revolting simile/metaphor combination, Lewis is alerting the reader to the severity of the human condition, forcing him to realize the great gap between our goodness and the goodness of God.
Gnawing Like Fire
"When I think of pain — of anxiety that gnaws like fire and loneliness that spreads out like a desert, and the heart-breaking routine of monotonous misery, or again of dull aches that blacken our whole landscape or sudden nauseating pains that knock a man’s heart out at one blow, of pains that seem already intolerable and then are suddenly increased, of infuriating scorpion-stinging pains that startle into maniacal movement a man who seemed half dead with his previous tortures — it 'quite o’ercrows my spirit.'” - p. 65 (VI: Human Pain)
This passage almost feels like Lewis is giving a presentation in a creative writing class on the appropriate use of similes and metaphors. This single sentence contains a large number of great, well-executed analogous literary devices to effectively portray the overwhelming, visceral horrors of pain. Literary critique aside, Lewis uses this chain of images to force his reader to come to grips with the oppressive reality of pain, ensuring that this does remain a purely intellectual, abstractly theoretical argument, but one applicable to real life and grounded in specific physical events.
