CLASSICAL ANTIQUITY, MIDDLE AGES 31 

 be the measure of all things, such as they appear here on earth, is nevertheless 

 itself subject to eternal laws, more infallible than those which the old phys- 

 icists saw in existence. The men who thus saved the Greek philosophy from 

 degenerating into empty rhetoric and worthless quibbles were two Atheni- 

 ans, Socrates and his disciple Plato. Socrates worked exclusively in the 

 ethical sphere; in this he sought for standards binding for all and emanating, 

 not from ancient tradition, but from the conscience of the private individual. 

 "Anyone can become virtuous if only he accepts a knowledge of virtue"; 

 that is his principal doctrine, and this knowledge he for his own part derived 

 from a divine voice in himself, which he desired also to awaken in his fellow 

 human beings. Nature did not interest him in the least; the streets of Athens 

 were his haunt, he said, and neither trees nor stones had anything to teach 

 him. 



Plato, a disciple of Socrates, generalized the doctrine of standards in 

 the ethical sphere which he learnt from his master, so that it was applied to 

 embrace the whole of the intellectual life of man. Born at Athens in 4x9 of 

 a distinguished family, he attached himself to Socrates at the age of about 

 twenty. Upon his master's death he left Athens and made extensive journeys, 

 afterwards returning to Athens, and there he established a school or college 

 known as the "Academy," which survived long after his death. He died 

 in 347. Like Pythagoras, he was a clever mathematician and, also like him, 

 combined ah inclination for the conclusive deductions of mathematics with 

 a strong attraction for the mystic. In the dialogue Thnaus, in which he pro- 

 pounds his theory of the origin of the universe, the functions of the human 

 body, and the relation of man to nature, he has evolved a history of creation, 

 poetically very fine, but at the same time purely mystical, testifying, it is 

 true, to his high ethical aims, but of no greater value as natural science than 

 any of the ancient popular cosmogonical myths. The world was created by 

 an eternal and perfect god, and therefore there can be no question of an endless 

 number of worlds, as Anaximander and Democritus made out, but only one, 

 and this single world must have received the most perfect of all shapes, the 

 sphere. He accepted Democritus' atomic theory to the extent that he believed 

 matter to be composed of particles, though these again are not of endless 

 variety, but are five in number, corresponding to the five regular polygons 

 of the geometry of space (Plato was one of the founders of this science and 

 one of the foremost geometricians of all time) — so that each element has 

 its atomic form: fire the pyramid, the earth the cube, the air the octahedron, 

 and water the icosahedron; the dodecahedron represents the heavens. Now, 

 this geometrical atomic form is in itself no more dogmatic than the entire 

 atomic theory of Democritus, but it forms the starting-point for a process 

 of natural speculation which is diametrically opposed to it. For while 

 Democritus takes as his starting-point the atoms and the matter formed by 



