RETROSPECT AND PROSPECT 



speed in a direct line forever, expresses such a law. 

 The fact that the gravitation pull is directly as the 

 mass and inversely as the square of the distance of the 

 bodies it involves, expresses another such law. The 

 fact that the planetary bodies of the solar system re- 

 volve in elliptical orbits under the joint influence of the 

 two laws just named, expresses yet another law. In 

 a word, then, these so-called "laws" are nothing more 

 than convenient formulae to express the classification 

 of observed facts. 



INDUCTIVE VERSUS DEDUCTIVE REASONING 



The ancient thinkers indulged constantly in what 

 we now speak of as deductive reasoning. They gave 

 heed to what we term metaphysical preconceptions 

 as to laws governing natural phenomena. The Greeks, 

 for example, conceived that the circle is the perfect 

 body, and that the universe is perfect; therefore, sun 

 and moon must be perfect spheres or disks, and all the 

 orbits of the heavenly bodies must be exactly circular. 

 We have seen that this metaphysical conception, dom- 

 inating the world for many centuries, exerted a con- 

 stantly hampering influence upon the progress of 

 science. There were numerous other instances of the 

 same retarding influence of deductive reasoning. Mod- 

 ern science tries to cast aside all such preconceptions. 

 It does not always quite succeed, but it makes a strenu- 

 ous effort to draw conclusions logically from observed 

 phenomena instead of trying to force observations into 

 harmony with a preconeived idea. Herein lies the 

 essential difference between the primitive method and 

 the perfected modern method. Neither the one nor 



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