  For instance, if I am in Athens now, then it has always in the past been the case that I would be in Athens (at some time). This principle gains historical plausibility from the fact that we find a version of it in Aristotle (On Interpretation 9, 18b9-11), and that another version of it was accepted by the Stoics (Cicero, On Divination 1.125). The second additional principle is