What does the wart learn while he is with the badger in the sword in the stone?

The Wart learns how to not be a tyrant (he doesn't just learn this from the badger however, but also from the hedgehog he encounters and threatens). Think of the Wart's social status compared to Kay's. He is a complete underdog. Then think about what he experiences with the hedgehog. He is the greater force here. By choosing not to kill the poor creature, he learns how to not be tyrannical to those who are of lower classes than himself. Then, with the wise badger, he learns about a story of the humans' origin. From Sparknotes.com : In the beginning, all animals looked like shapeless embryos. God offered to alter each of them in three different ways. The animals chose things like claws for digging and large teeth for cutting. Man was the last embryo to choose, and he chose to stay just as God made him. God therefore gave him dominion over the animals and the ability to use any tool he wanted. Here the Wart learns to be content with what is given to him, even if he is less fortunate than others.