““about runaway trolleys!” This is an example of what Kant would call heteronomous determination —doing something for the sake of something else, for the sake of something else, and so on. When we act heteronomously, we act for the sake of ends given outside us. We are instruments, not authors, of the purposes we pursue. Kant’s notion of autonomy stands in stark contrast to this. When we act autonomously , according to a law we give ourselves, we do something for its own sake, as an end in itself. We cease to be instruments of purposes given outside us. This capacity to act autonomously is what gives human life its special dignity. It marks out the difference between persons and things.””
