CHAPTER VI. 



METHOD OF DISCOVERING CAUSAL LAWS BY ANALYSIS OF 

 FACTS : OBSERVATION AND EXPERIMENT. 



238. OBSERVATION AND SELECTION : INITIAL PRECAU 

 TIONS. It is the aim of induction to discover the causes of 

 phenomena, to verify as far as possible the laws according to 

 which we suppose these causes to act, and so to explain the phe 

 nomena by means of these laws and causes. We have examined, 

 so far, the general scope of the inductive method, the ways in 

 which a knowledge of laws and causes is suggested, and the logi 

 cal character of the procedure by which hypotheses are verified. 

 We have next to investigate, in some detail, the functions of ob 

 servation and experiment, with the more directly practical purpose 

 of bringing to light certain useful rules for the proper conduct and 

 application of these processes. 



The events or occurrences of nature are complex and inter 

 related with one another. None of them stands apart in a state 

 of isolation. It is because they are so intimately interwoven that 

 we find it difficult to single out and mark off a &quot; phenomenon &quot; 

 for investigation, to analyse fully its surroundings, and to lay bare 

 those amongst them with which it is causally connected. Yet 

 we must do all this before we can say whether or not our sup 

 posed cause the object of our hypothesis is the real cause of 

 the phenomenon. 



We observe an event occurring in certain circumstances or 

 surroundings. In our initial observation we have evidently to select 

 the phenomenon, and limit it or mark it off from its antecedent, 

 concomitant, and subsequent circumstances. We next want to 

 bring to light its cause, to find out the natural law according to 

 which it occurs. We therefore make some supposition or hy 

 pothesis as to the factor or group of factors with which it is 

 causally connected. * This, too, involves selection on our part. And 

 finally, we want to verify our hypothesis, i.e. to find out, if pos 

 sible, whether our supposed cause is the sufficient and indispens- 



162 



