In this excerpt from Alice in Wonderland, the Cat explains to Alice that everyone in their world is mad, including both of them. The quote emphasizes the whimsical and nonsensical nature of Wonderland, where normal rules do not apply, and madness is a common trait among its inhabitants.

The conversation highlights the playful and surreal tone of the story, where Alice questions the Cat about madness, and the Cat responds that Alice must be mad to be there. This exchange underscores the theme of questioning reality and the blurred lines between sanity and madness in Lewis Carroll's fantastical universe.