io THE POPULAR SCIENCE MONTHLY. 



feeling ; they see that men in other countries and in other ages have 

 held to very different doctrines from those which they themselves 

 have been brought up to believe ; and they cannot help seeing that it 

 is the mere accident of their having been taught as they have, and 

 of their having been surrounded with the maimers and associations 

 they have, that has caused them to believe as they do and not far 

 differently. And their candor cannot resist the reflection that there 

 is no reason to rate their own views at a higher value than those 

 of other nations and other centuries ; and this gives rise to doubts in 

 their minds. 



They will further perceive that such doubts as these must exist 

 in their minds with reference to every belief which seems to be deter- 

 mined by the caprice either of themselves or of those who origi- 

 nated the popular opinions. The willful adherence to a belief, and 

 the arbitrary forcing of it upon others, must, therefore, both be given 

 up, and a new method of settling opinions must be adopted, wdrich 

 shall not only produce an impulse to believe, but shall also decide 

 what proposition it is which is to be believed. Let the action of nat- 

 ural preferences be unimpeded, then, and under their influence let men, 

 conversing together and regarding matters in different lights, grad- 

 ually develop beliefs in harmony wdth natural causes. This method 

 resembles that by which conceptions of art have been brought to ma- 

 turity. The most perfect example of it is to be found in the history 

 of metaphysical philosophy. Systems of this sort have not usually 

 rested upon any observed facts, at least not in any great degree. 

 They have been chiefly adopted because their fundamental proposi- 

 tions seemed " agreeable to reason." This is an apt expression ; it 

 does not mean that which agrees with experience, but that which we 

 find ourselves inclined to believe. Plato, for example, finds it agree- 

 able to reason that the distances of the celestial spheres from one an- 

 other should be proportional to the different lengths of strings which 

 produce harmonious chords. Many philosophers have been led to 

 their main conclusions by considerations like this ; but this is the 

 lowest and least developed form which the method takes, for it is 

 clear that another man might find Kepler's theory, that the celestial 

 spheres are proportional to the inscribed and circumscribed spheres 

 of the different regular solids, more agreeable to his reason. But the 

 shock of opinions will soon lead men to rest on preferences of a far 

 more universal nature. Take, for example, the doctrine that man only 

 acts selfishly that is, from the consideration that acting in one way 

 will afford him more pleasure than acting in another. This rests on 

 no fact in the world, but it has had a wide acceptance as being the 

 only reasonable theory. 



This method is far more intellectual and respectable from the point 

 of view of reason than either of the others which w r e have noticed. 

 But its failure has been the most manifest. It makes of inquiry 



