EXCURSIONS OF AN EVOLUTIONIST 



ent minds. But unity of belief in religious mat- 

 ters is not very likely to be reached in any such 

 way, for the conditions of the case are totally 

 different from those of scientific discussion. The 

 difference may be best appreciated by recall- 

 ing the useful distinction drawn by positivism 

 between science and metaphysics. According 

 to positivism, the essential distinction between a 

 scientific hypothesis, such as the undulatory the- 

 ory of light, and a metaphysical hypothesis, such 

 as the Leibnitzian theory of preestablished har- 

 mony, is that the one admits of verification 

 whether by observation, experiment, or deduc- 

 tion while the other does not. Or, from 

 another point of view, the one may be made a 

 working hypothesis from which independent in- 

 quirers will arrive at mutually congruous results, 

 while the other cannot. This distinction is one 

 of the very few points made by positivism which 

 have been generally adopted into modern phi- 

 losophy ; but the use which positivists have made 

 of it is by no means philosophical. Comte him- 

 self set an inordinate value upon unity of belief, 

 and in this his disciples have generally followed 

 him ; and the way in which they propose to se- 

 cure such unity is simply to ignore all problems 

 whatever in which scientific methods of demon- 

 stration are not accessible. This seems like pay- 

 ing an exorbitant price for a privilege of very 

 doubtful value. But without following the pos- 

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