THE DISCIPLINARY VALUE OF GEOGRAPHY 115 



advantage inspect the opposed arrays, with the intention of seeing how 

 closely any battalion of consequences matches the battalion of facts. 

 In making this inspection, the comparer must evidently give particular 

 attention to the facts from which an invention did not spring ; and look 

 closely to see how successfully they are matched by the consequences of 

 the invention. There must be no pressure to force an agreement where 

 none exists; no constraining of the facts or torturing of the conse- 

 quences to make them look like each other; but simply a fair-minded 

 comparison, followed by a clear unbiased report as to where agreement 

 and disagreement occur. 



Preliminary Judgment. — If two rival hypotheses have yielded only 

 identical consequences, all of which agree nicely with the corresponding 

 facts, no decision in favor of either hypothesis can be made, and judg- 

 ment must be suspended. The comparer must then ask the deducer if 

 he can not find unlike consequences of the rival hypotheses ; and if such 

 are found close attention must be given to the degree of success with 

 which they match the corresponding facts. Evidently, then, some con- 

 sequences have a greater value than others in discriminating among 

 rival hypotheses. If the consequences which are peculiar to one hypoth- 

 esis match the appropriate facts, while the contrasted consequences of 

 other hypotheses fail to do so, then a higher value may be given to this 

 one of the several rival hypotheses, although before it had no greater 

 value than its now defeated competitors. 



Revision. — It will often happen, when confrontation is made and 

 an encouraging amount of agreement is found between the consequences 

 of a certain hypothesis and the corresponding facts of observation, that 

 the agreement is nevertheless in some respects imperfect. It may be 

 that, for some of the facts, no corresponding consequences have been 

 deduced; or that, for certain deduced consequences, there are no cor- 

 responding facts. Then the investigator must revise his work. He 

 must return to the stage of deduction, and look closely to see if those 

 consequences which are only partly successful in meeting the facts, 

 were rightly deduced; he must inquire if the absence of a certain con- 

 sequence, with which some weU ascertained fact ought to be matched, 

 is perhaps due to oversight in his deduction. He must examine with 

 particular care all the principles, introduced by memory from previous 

 acquisition, to see if they are safely established and correctly applied; 

 he must be especially careful not to overlook any tacit postulate, which, 

 without being consciously recognized as such, has nevertheless been 

 taken for granted without sufficient proof, and used as an essential 

 basis for some of his deductions. He must go still farther back and 

 modify his inventions in one way or another, in the hope that, after such 

 modification, some one of them may lead to new consequences that will 

 better than before fit the previously unmatched facts: hence it is im- 



