Xenophanes - Physical Ideas

Physical Ideas

Xenophanes wrote about two extremes predominating the world: wet and dry (water and earth). These two extreme states would alternate between one another and with the alteration human life would become extinct then regenerate (or vice versa depending on the dominant form). The idea of alternating states and human life perishing and coming back suggests he believed in the principle of causation; another distinguishing step that Xenophanes takes from Ancient philosophical traditions to ones based more on scientific observation. The argument can be considered a rebuke to Anaximenes' air theory. A detailed account of the wet and dry form theory is found in Hippolytus' Refutation.

Xenophanes concluded from his examination of fossils that water once must have covered all of the Earth's surface. The use of evidence is an important step in advancing from simply stating an idea to backing it up by evidence and observation.