INFLUENCE OF ABSTRACT THOUGHT 17 



that all things are water. Attempts have been 

 made to add to this statement, and to explain it 

 away. Its great interest for the history of thought 

 lies in the fact that it is the result of seeking the 

 constant in the variable, the unitary principle in the 

 multiple phenomena of nature. This abstract and 

 general view (though perhaps suggested by the 

 Babylonian belief that the world originated in a 

 watery chaos, or by the teaching of Egyptian priests) 

 was preeminently Greek, and was the first of a 

 series of attempts to discover the basis or origin of 

 all things. One of the followers of Thales taught 

 that air was the fundamental principle ; while Her- 

 aclitus, anticipating to some extent modern theories 

 of the origin of the cosmos, declared in favor of a 

 fiery vapor subject to ceaseless change. Empedo- 

 cles, the great philosopher-physician, first set forth 

 the doctrine of the four elements earth, air, fire, 

 and water. For Democritus indivisible particles or 

 atoms are fundamental to all phenomena. It is evi- 

 dent that the theory of Thales was a starting point 

 for Greek abstract thought, and that his inclination 

 to seek out principles and general laws accounts for 

 his influence on the development both of philosophy 

 and the sciences. 



Pythagoras, on the advice of Thales, visited Egypt 

 in the pursuit of mathematics. There is reason to 

 believe that he also visited Babylonia. For him and 

 his followers mathematics became a philosophy 

 almost a religion. They had discovered (by experi- 

 menting with the inonochord, the first piece of 

 physical-laboratory apparatus, consisting of a tense 

 harpstring with a movable bridge) the effect on the 



