 Cavendish takes it to be obvious that only material things move. That is to say, there is no immaterial motion. She also takes it to be obvious that if a person is thinking and their body partakes of motion, their mind partakes of motion as well. In the current day we might be at the airport, thinking about a philosophical question, and then we might continue to think about the question midflight, and then we might finally give the question a rest when we have arrived at our destination. Our thinking took place at the airport, and on the plane, and at our final stop. Taking issue with the ancient Greek philosopher Protagoras, she writes,