 In many other ancient and medieval logicians, “must” claims are understood as universal generalizations about actual items (even if they are not always understood as universal generalizations on “formal” schemata). Especially prominent is Diodorus' view that a proposition is necessary just in case it is true at all times (see Mates 1961, III, §3). Note that this makes sense of the idea that (2) must be true but, say, “People watch TV” could be false, for surely this sentence was not true in Diodorus' time. Diodorus' view appears to have been very common in the Middle Ages, when authors like William of Sherwood and Walter Burley seem to have understood the perceived necessity of conditionals like (2) as truth at all times (see Knuuttila 1982, pp. 348–9). An understanding of necessity as eternity is frequent also in later authors; see e.g., Kant, Critique of Pure Reason, B 184. In favor of the mentioned interpretation of Aristotle and of the Diodorean view it might be pointed out that we often use modal locutions to stress the consequents of conditionals that follow from mere universal generalizations about the actual world, as in “If gas prices go up, necessarily the economy slows down”.