To Prodicus we owe the well-known tale of Hercules at the parting of the ways, when Virtue on the one hand, and Pleasure on the other, each invite him to join company with her[51]. This tale we shall find to be a favourite with the Roman philosophers. The same Prodicus introduced a doctrine afterwards taken up by the Cynics and the Stoics in succession, that of the ‘indifference’ of external advantages as distinct from the use to which they are applied. He also propounded theories as to the origin of the gods of mythology, explaining some of them as personifications of the powers of nature, others as deified benefactors of the human race[52]; theories which later on were adopted with zeal by the Stoic Persaeus[53]. To another sophist, HIPPIAS of Elis, we owe the doctrine of the ‘self-sufficiency’ of virtue, again adopted both by Cynics and Stoics[54]. ANTIPHON was not only the writer of an ‘Art of Consolation,’ but also of a treatise of extraordinary eloquence on political concord and the importance of education. ‘If a noble disposition be planted in a young mind, it will engender a flower that will endure to the end, and that no rain will destroy, nor will it be withered by drought[55].’ [Sidenote: The Materialists.] =43.= Amongst the sophists of Athens was counted ANAXAGORAS, born at Clazomenae about 500 B.C., and a diligent student of the Ionic philosophers. But in his explanation of nature he broke away from ‘hylozoism’ and introduced a dualism of mind and matter. ‘From eternity all things were together, but Mind stirred and ordered them[56].’ More famous was his contemporary EMPEDOCLES of Agrigentum, whose name is still held in honour by the citizens of that town. In him we first find the list of elements reaching to four, earth, air, fire, and water; and the doctrine that visible objects consist of combinations of the elements in varying proportions, first brought together by Love, then separated by Hatred. Just in so far as Empedocles abandoned the quest after a single origin for all things, his conceptions became fruitful as the basis of the more limited study now known as Chemistry. His work was carried further by LEUCIPPUS and DEMOCRITUS, both of Abdera, who for the four elements substituted invisible atoms, of countless variety, moving by reason of their own weight in an empty space. This simple and powerful analysis is capable of dealing effectively with many natural phenomena, and with comparatively slight alterations is still held to be valid in chemical analysis, and exercises a wide influence over the neighbouring sciences of physics and botany. When however (as has frequently been the case both in ancient and modern times) the attempt is made to build upon it a general philosophical system, its failure to explain the cohesion of matter in masses, the growth of plants and animals, and the phenomena of mind, become painfully apparent. Such attempts roughly correspond