“If I hadn’t spent so much time studying Earthlings,” said the Tralfamadorian, “I wouldn’t have any idea what was meant by ‘free will.’ I’ve visited thirty-one inhabited planets in the universe, and I have studied reports on one hundred more. Only on Earth is there any talk of free will.”
This quotation comes at the end of Chapter 4, as Billy listens to his captors describe the true nature of time. These words reveal that not only do Tralfamadorians have a completely deterministic view of the universe in which every moment is structured beyond the control of its participants, but that they also lack an awareness of the possibility of free will. The alien who talks to Billy is an exception, having encountered the peculiarly human hang-up in his travels. But he maintains that humans, alone among all beings in the universe, believe in the illusion of free will. His emphasis on the idea of “studying” humans and inhabitants of other planets makes humans (and their conception of free will) and other non--Tralfamadorians seem like bizarre exceptions to the rule of nature. He thus performs a reversal of the human tendency to think of alien life as abnormal.