480 SCIENCES OF THE EARTH 



framed to fit those that first arrest attention naturally fits the oft- 

 recurrent phenomena of the same class. While there may be really 

 no new evidence, nor any real test, nor any further inquiry into the 

 grounds of the theory, its repeated application with seeming success 

 leads insidiously to the delusion that it has been strengthened by addi- 

 tional investigation. Unconsciously then it begins to direct observa- 

 tion to the facts it so happily elucidates. Unconsciously the facts to 

 which it gives no meaning become less impressive and fall into neglect. 

 Selective observation creeps insidiously in and becomes a persistent 

 habit. Soon also affection is awakened with its blinding influence. 

 The authorship of an original explanation that seems successful easily 

 begets fondness for the intellectual child. This affection adds its 

 alluring influence to the previous tendency toward an unconscious 

 selection. The mind lingers with pleasure upon the facts that fall 

 happily into the embrace of the theory, and feels a natural indiffer- 

 ence toward those that assume a refractory or meaningless attitude. 

 Instinctively there is a special searching-out of phenomena that sup- 

 port the theory; unwittingly also there is a pressing of the theory to 

 make it fit the facts and a pressing of the facts to make them fit the 

 theory. When these biasing tendencies set in, the mind soon glides 

 into the partiality of paternalism, and the theory rapidly rises to a 

 position of control. Unless it happens to be the true one, all hope of 

 the best results is gone. The defects of this method are obvious and 

 grave. 



It is safe to say, however, that under this method, with all its de- 

 fects, many facts will be gathered that an observer of colorless atti- 

 tude would have quite overlooked. The reverse may doubtless also 

 be said. An effort to avoid the dangers at once of the colorless Scylla 

 and the biasing Charybdis gave rise to 



The Method of the Working Hypothesis 



This may be regarded as the distinctive feature of the methodology 

 of the last century. This differs from the method of the ruling theory 

 in that the working hypothesis is made a means of determining facts, 

 not primarily a thesis to be established. Its chief function is the sug- 

 gestion and guidance of lines of inquiry; inquiry not for the sake of 

 the hypothesis, but for the sake of the facts and tkeir final elucida- 

 tion. The hypothesis is a mode rather than an end. Under the 

 ruling theory, the stimulus is directed to the finding of facts for the 

 support of the theory. Under the working hypothesis, the facts are 

 sought for the purpose of ultimate induction and demonstration, the 

 hypothesis being but a means for the more ready development of facts 

 and their relations, particularly their relations. 



It will be seen that the distinction is somewhat subtle. It is rarely 



