286 G. K. Gilbert — Inculcation of Scientific Method. 



which precedes, and the necessary antecedent of that which fol- 

 lows. The rising of the sun is consequent on the rotation of the 

 earth. It is the logical antecedent of morning light. Morning 

 light is in turn the consequent of sunrise and the antecedent of 

 numerous other phenomena. If we examine any link of the 

 chain, we find that it has more than one antecedent and more 

 than one consequent. The rising of the sun depends on the 

 position of the earth's axis as well as on its rotation, and it 

 causes morning heat as well as morning light. Antecedent and 

 consequent relations are therefore not merely linear, but con- 

 stitute a plexus ; and this plexus pervades nature. 



Relational classification may be considered as of two sorts, 

 first linear, and second, coordinate as determined by linear, 

 that is to say, phenomena are linearly arranged in chains of 

 sequence, and they are coordinately arranged in natural classes. 

 A natural class is a group of coordinate facts having the same 

 antecedents. 



It is the province of research to discover the antecedents of 

 phenomena. This is done by the aid of hypothesis. A phe- 

 nomenon having been observed, or a group of phenomena hav- 

 ing been established by empiric classification, the investigator 

 invents an hypothesis in. explanation. He then devises and 

 applies a test of the validity of the hypothesis. If it does not 

 stand the teat he discards it and invents a new one. If it sur- 

 vives the test, he proceeds at once to devise a second test. 

 And he thus continues until he finds an hypothesis that re- 

 mains unscathed after all the tests his imagination can suggest. 



This, however, is not his universal course, for he is not re- 

 stricted to the employment of one hypothesis at a time. There 

 is indeed an advantage in entertaining several at once, for then 

 it is possible to discover their mutual antagonisms and incon- 

 sistencies, and to devise crucial tests, — tests which will necessa- 

 rily debar some of the hypotheses from further consideration. 

 The process of testing is then a process of elimination, at least 

 until all but one of the hypotheses have been disproved. 



In the testing of hypotheses lies the prime difference between 

 the investigator and the theorist. The one seeks diligently for 

 the facts which may overthrow his tentative theory, the other 

 closes his eyes to these and searches only for those which will 

 sustain it. 



Evidently, if the investigator is to succeed in the discovery 

 of veritable explanations of phenomena, he must be fertile in 

 the invention of hypotheses and ingenious in the application of 

 tests. The practical questions for the teacher are, whether it is 

 possible by training to improve the guessing faculty, and if so, 

 how it is to be done. To answer these, we must give attention 

 to the nature of the scientific guess considered as a mental 



