"love, by which there are who think The world ofttimes converted into chaos"

(Canto 12, lines 42-43)

Referring to Empedocles' theory of the four elements (fire, air, water, earth). Empedocles believed that two forces called Love and Strife decided the mixture and separation of these elements and thereby produced all things and changes observed in the world: Strife was the dissociating power, which contributed to order in the universe, while Love, the attractive force, contributed to chaos. Dante probably learned about this theory in Aristotle's "Metaphysics", where the latter criticizes it.