CHAPTER IV 

 THE BEGINNINGS OF SCIENCE 



SCIENCE is said to have begun with Thales. Of 

 Thales himself we know but little, and that through 

 writers like Aristotle who lived two hundred years 

 later. Specifically, he is credited by the latter with 

 accounting for the attraction of iron by a lodestone, by 

 assuming a cause inherent in the stone instead of super- 

 natural influences, as did his contemporaries. With 

 him our knowledge of magnetism begins. 



Thales, also, felt the need of accounting for the 

 various kinds of matter in terms of some common 

 element. Twenty-four centuries passed between his 

 suggestion and the common acceptance of the atomic 

 theory which describes all matter in terms of a compara- 

 tively few elements in various proportion. But Thales 

 envisaged a single element. This accords with the 

 extension of the atomic theory, the " electron theory," 

 which is accepted to-day. Atoms of all substances 

 are now known to be composed of small particles of 

 electricity, called electrons, which are all alike without 

 regard to the chemical element from which they may 

 be obtained. 



All Thales really did was to direct men's attention 

 to the problem, still incompletely solved, of the com- 

 position of matter. In the centuries since his time 

 and more especially in the last, progress has been made 



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