Courage in The Lion, the Witch, and the Wardrobe is not a feeling but a way that you behave. Although you might feel despairing, frightened, or sick, you can still behave bravely. Bravery is one of the most valuable virtues. It cannot be learned, but good people will find that they have unknown reserves of strength in difficult moments. Courage may mean the ability to face certain defeat, pain, suffering, or even death with patience and fortitude. There is such a thing as foolhardiness; it is possible that bravery can be misplaced in certain circumstances. The courage of a child to stand up to a nightmarish fear might be just as valuable in this book as the brave deeds of a great warrior.
Feeling courageous is unimportant in The Lion, the Witch, and the Wardrobe; the important thing is to behave courageously no matter how you feel.
Aslan defies everyone's expectations of courageous behavior by showing bravery and fortitude in the face of certain death, rather than simply killing the Witch immediately.