“Anaximenes ... also says that the underlying nature is one and infinite ... but not undefined as Anaximander said but definite, for he identifies it as air; and it differs in its substantial nature by rarity and density. Being made finer it becomes fire; being made thicker it becomes wind, then cloud, then (when thickened still more) water, then earth, then stones; and the rest come into being from these.” MadeSaidStillsMatterEarthScienceWaterFireAirWindStonesInfiniteCloudsDefiniteDensityRarityUndefined Author:Theophrastus