Fate and free will have been smacking each other upside the head for almost as long as humans have had heads to smack. A Wrinkle in Time plugs this battle into another ongoing debate: what makes people happy? The giant brain of Camazotz, IT, would have it that total submission to another's will is where true bliss lies, but the humans of the story aren't so sure. Does the freedom to make mistakes bring happiness or sadness? Is one possible without the other? Is a happy society different from a happy individual, and which is better to pursue?
While the children seem to be making decisions, everything they do is set up by the Mrs. Ws so their choices are not truly free.
The novel's portrayal of Camazotz suggests that happiness is meaningless in the absence of free will.