Hippo, a Greek philosopher and natural scientist, classed with the Ionian or physical school. He was probably a contemporary of Archelaus and lived chiefly in Athens. Aristotle declared that he was unworthy of the name of philosopher, and, while comparing him with Thales in his main doctrine, adds that his intellect was too shallow for serious consideration. He held that the principle of all things is moisture (τὸ ὑγρόν); that fire develops from water, and from fire the material universe. Further he denied all existence save that of material things as known through the senses, and was, therefore, classed among the “Atheists.” The gods are merely great men canonized by popular tradition. It is said that he composed his own epitaph, wherein he claims for himself a place in this company.