Love
Revenge
"What is the thing women most desire? Beware the axe and say as I require."
As the knight is charged with rape and he is required to answer the queen's one question, he runs into the problem of his ability to answer. This brings about the theme of knowledge prevalent in the story. As the knight travels around, none of the people he asks can give him the same knowledge or ideas, until he runs into the old woman. In his quest for knowledge, he is introduced to another theme, one of trickery, when the old woman tricks him into marrying her as she knows that he in honorable and wouldn't refuse.
"My lady and my love, my dearest wife, I leave the matter to your wise decision."
The knight demonstrates the knowledge that he has learned when he allows his wife to make the decision herself, giving her the power and getting the best of both worlds for himself. In a way, he also gets revenge for the trickery that the woman pulled on him at the beginning of the story, as it seems that she did not notice that he followed her own advice. In the end, by allowing the wife to make the decision, he not only received a beautiful wife, but a trustworthy and loving one as well.
The theme of variety of opinion when regarding knowledge is something that remains to be prevalent in the world today. Depending on opinion, the advice or information that you could receive is vastly different. With so many different ways of thinking, it is often impossible to find the "correct" answer unless it is backed by science or another tangible means of proving something's existence. Using the same example as The Wife of Bath, the question of what women want would still have a variety of answers depending on who you asked.
The idea of a quest for knowledge is something that can still be seen today in the form of, for example, religious pilgrimages. During pilgrimages from one place to a far-away church, people will walk long distances for the purpose of feeling more knowledgeable or feeling closer to God. The reliquaries, which contain dead parts of Saints, are something that everyone travels to see. This can be compared to the knight's quest to find the information that he desired, although it was not of religious roots.