Abstract
As Aristotle saw it, the modus operandi of nature is frequently irregular and unruly. And this accords with the structure of the universe, with regularity predominant in the trans-lunar realm and regularity prominent in the cis-lunar. This circumstance opens the way to the different sorts of natural laws: those which are strictly universal and those which function only normally and “for the most part.” And knowing to what extent exactness, regularity, and universality can be expected in different areas of inquiry was, for Aristotle, the very touchstone of scientific wisdom and sophistication.