Note 38 — FIRST PART. The Story of Astronomy from Primitive Times until the Age of Dante. (continued 2)

Thus, (he adds) time also is threefold, for we have Beginning, Middle, and End. Therefore we apply three to Divine things, and also in common speech we call two “both,” and only say “all” when we reach three, following Nature’s law. The Pythagoreans say “The all and all things are bounded by the number three.”—De Cœlo I. 1.