5i6 POPULAR SCIENCE MONTHLY. 



if not always so held ostensibly, himself, and the other part being the 

 aggregate of whatever else was left over. Though dimly perceived 

 and of little account in its effects, this is, apparently, the working 

 hypothesis of many men in the civilized society of to-day. But the 

 magnitude of the latter part and its inexorable relations to man seem 

 to have led him speedily to the adoption of the second hypothesis, 

 namely, that the latter part, or world external to himself, is also the 

 abode of sentient beings, some of a lower and some of a higher order 

 than man ; their role tending on the whole to make his sojourn on this 

 planet tolerable and his exit from it creditable, while yet wielding at 

 times a more or less despotic influence over him. 



How the details of these hypotheses have been worked out is a matter 

 of something like history for a few nationalities, and is a matter absorb- 

 ing the attention of anthropologists, archeologists and ethnologists as 

 it concerns races in general. Without going far afield in these pro- 

 foundly interesting and instructive details, it may suffice for the present 

 purposes to cite two facts which seem to furnish the key to a substan- 

 tially correct interpretation of subsequent developments. 



The first of these is that the early dualistic and antithetical visual- 

 ization of the problem in question has persisted with wonderful tenacity 

 down to the present day. The accessible and familiar was set over 

 against the inaccessible and unfamiliar; or what we now call the 

 natural, though intimately related to, was more or less opposed to the 

 supernatural; the latter being, in fact, under the uncertain sway of, 

 and the former subject to the arbitrary jurisdiction of, good and evil 

 spirits. 



The second fact is that man thus early devised for the investigation 

 of this problem three distinct methods, which have likewise persisted 

 with equal tenacity, though with varying fortunes, down to the present 

 day. The first of these is what is known as the a priori method. It 

 reasons from subjective postulates to objective results. It requires, 

 in its purity, neither observation nor experiment on the external world. 

 It often goes so far, indeed, as to adopt conclusions and leave the as- 

 signment of the reasons for them to a subsequent study. The second 

 is known as the historico-critical method. It depends, in its purity, 

 on tradition, history, direct human testimony and verbal congruity. It 

 does not require an appeal to Nature except as manifested in man. It 

 limits observation and experiment to human affairs. The third is the 

 method of science. It begins, in its elements, with observation and ex- 

 periment. Its early applications were limited mostly to material things. 

 In its subsequent expansion it has gained a footing in nearly every 

 field of thought. Its prime characteristic is the insistence on objective 

 verification of its results. 



