  We may reasonably conclude from several surviving fragments and a large number of testimonia that Xenophanes was well aware of the teachings of the Milesian philosopher-scientists (Thales, Anaximander, and Anaximenes), and sought to improve on them. While many of the details of his own ‘scientific’ views remain obscure, the range and interconnectedness of his interests make him an important figure in the development of Ionian scientific theory. Theodoretus, Stobaeus, and Olympiodorus (all in A 36) credit him with a view of earth as the archê or “first principle” of all things. Yet Galen (also in A36) rejects this attribution, and B29 equates “all things which come into being and grow” with “earth and water”. A two-substance archê would, moreover, be compatible with the many references to physical mixtures. A33 credits Xenophanes with a view of the sea as containing many mixtures, while B37 notes the presence of water in rocky caves, and A50 reports a view of the soul as earth and water. Insofar as some natural bodies are described as consisting entirely of water (or of a part of water, as in A46 where “the sweet portion” of the water is drawn up from the sea and separated off), it would be best to understand Xenophanes’ “two-substance theory” in a distributed sense: all things are either earth, or water, or earth combined with water.