SCIENCE IN THE ANCIENT WORLD 39 



as was then possible, to answer the question, " Of what 

 and in what way is the world made ? " 



Thales was followed by Anaximenes, who seems to 

 have been the first clearly to recognize that the heavens 

 revolved round the pole star, and to draw the con- 

 clusion that the visible dome of the sky was half of a 

 complete sphere at the centre of which was the earth. 

 Till Anaximenes gained this new outlook, the earth had 

 been imagined as a floor with a solid base of limitless 

 depth. It was now represented as a flattened cylinder, 

 floating within the celestial sphere, which, carrying 

 the stars with it as fixed luminous points, revolved 

 about the earth as the centre of all things. Thus, in 

 its day, the now discredited geocentric theory was an 

 immense advance over the mythological ideas which 

 preceded it. A false hypothesis, if it serve as a 

 guide for further enquiry, may, at the right stage 

 of science, be as useful as, or more useful than, a 

 truer one for which acceptable evidence is not yet at 

 hand. 



In this case, though a better theory was shortly 

 forthcoming, the time was not ripe, and, for many 

 centuries, mankind returned to the earlier view as 

 giving a more convincing picture. The school of 

 Pythagoras (c. 530) has been held to favour a mystical 

 attitude of mind, as opposed to the rationalistic 

 tendencies of the men of Miletus. A religious refor- 

 mation was probably involved in their teachings, and 

 in them we first meet with the conception of contrasting 

 principles, Good and Evil, Light and Darkness. The 

 Pythagoreans replaced Anaximenes' moving sky by a 

 moving earth, which was imagined to revolve round a 

 central point fixed in space like a stone at the end of a 



