METHODS OF THE EARTH-SCIENCES 481 



if ever perfectly sustained. A working hypothesis may glide with the 

 utmost ease into a ruling theory. Affection may as easily cling about 

 a beloved intellectual child under the name of a working hypothesis 

 as under any other, and may become a ruling passion. The moral 

 atmosphere associated with the working hypothesis, however, lends 

 some good influence toward the preservation of its integrity. The 

 author of a working hypothesis is not presumed to father or defend 

 it, but merely to use it for what it is worth. 



Conscientiously followed, the method of the working hypothesis is 

 an incalculable advance upon the method of the ruling theory, as it is 

 also upon the method of colorless observation; but it also has serious 

 defects. As already implied, it is not an adequate protection against 

 a biased attitude. Even if it avoids this, it tends to narrow the scope 

 of inquiry and direct it solely along the lines of the hypothesis. It 

 undoubtedly gives acuteness, incisiveness, and thoroughness in its own 

 lines, but it inevitably turns inquiry away from other lines. It has 

 dangers, therefore, akin to its predecessor, the ruling theory. 



A remedy for these dangers and defects has been sought in 



The Method of Multiple Working Hypotheses l 



This differs from the method of the simple working hypothesis in 

 that it distributes the effort and divides the affections. It is thus in 

 some measure protected against the radical defects of the two previous 

 methods. The effort is to bring up into distinct view every rational 

 explanation of the phenomenon in hand and to develop into working 

 form every tenable hypothesis of its nature, cause, or origin, and to 

 give to each of these a due place in the inquiry. The investigator 

 thus becomes the parent of a family of hypotheses; and by his pater- 

 nal relations to all is morally forbidden to fasten his affections unduly 

 upon any one. In the very nature of the case, the chief danger that 

 springs from affection is counteracted. Where some of the hypotheses 

 have been already proposed and used, while others are the investiga- 

 tor's own creation, a natural tendency to bias arises, but the right use 

 of the method requires the impartial adoption of all into the working 

 family. The investigator thus at the outset puts himself in cordial 

 sympathy and in the parental relations of adoption, if not of author- 

 ship, with every hypothesis that is at all applicable to the case under 

 investigation. Having thus neutralized, so far as may be, the partial- 

 ities of his emotional nature, he proceeds with a certain natural and 

 enforced erectness of mental attitude to the inquiry, knowing well that 

 some of the family of hypotheses must needs perish in the ordeal of 

 crucial research, but with a reasonable expectation that more than 



1 In this sketch I have drawn freely upon my paper on " The Method of Mul- 

 tiple Working Hypotheses," Journ. Geol., v, 1897. 



