 It is also worth noting that Leibniz does not limit his doctrine of final causation to the conscious activity of rational agents, for he holds that a mental state can function as a final cause without our being aware of it. In a letter to Sophie Charlotte, Leibniz writes: “So that even in our instinctive or involuntary actions, where it seems only the body plays a part, there is in the soul an appetite for good or an aversion to evil which directs it, even though our reflection is not able to pick it out in the confusion” (GP III, 347; WF 224f.). Nor does Leibniz restrict final causation to rational agents. (Nor does Aristotle for that matter.) The final cause of a plant or an animal is not a plan or intention. Rather, it is whatever lies at the end of the regular series of developmental changes that it undergoes. 