Aristotle's Argument for Self-Motion

If Descartes knew what self-motion was, he wouldn't try to argue against Aristotle the way he does. He's trying to catch Aristotle out by using his premises and just saying, look, we have this new evidence about how motion actually occurs. I feel like the wooden Descartes just take a mechanistic view of metabolism and say it's a species of local motion. That form of argument presupposes that he thinks he has the correct sense of motion, the way that Aristotle intended it.