542 THE ROYAL SOCIETY OF CANADA 



of 20-3/33-3 (or 20 -3:13 = 1-56:1 = 156: 100) of the superior measure 

 that this insurance is against loss of his property by fire. Or, again, 

 if it be placed in evidence that he personally holds insurance of $1,000, 

 not against fire, this will establish a conclusion with a degree of prob- 

 ability of 8-5/13 (or 8-5:4-5 = 1-888:1 = 188-8:100) of the superior 

 measure that the insurance is on his life. In the first conclusion the 

 favorable chances are more than half again as many as the unfavor- 

 able, while in the second the favorable chances exceed the unfavorable 

 by over 88 per cent., a number not materially short of twice as many. 

 In practice, however, value would not be attached to either of them; 

 for instance, a prospective or actual creditor of John Doe, if the secur- 

 ity depended on the insurance of the debtor's property against fire, 

 would not consider the needs of the case as met in any sense by the 

 first of the above items of information or evidence, nor by the second, 

 if his security depended on the insurance of John Doe's life. On the 

 contrary, the creditor would consider these items and the probable 

 conclusions based on them to be without practical, as they are without 

 scientific, significance. 



Probability Tested Theoretically by the Fundamental and 

 Methodic Principles of Science. 



a. Probability tested by the fundamental principles of science. 

 The fundamental principles (Part I, 139, 140) which bear upon the 

 scientific status of probability, are the 1st and 3rd, as follows: 



1. The primary attitude toward all conclusions, whether probable 

 or improbable, must be one of non-acceptance, accompanied by a willing- 

 ness to make thorough examination by correct processes and to accept 

 those conclusions, and those only, which are shown thereby to be neces- 

 sary. 



3. A correct process is one that rightly followed leads necessarily 

 to a correct result. 



Under the 1st principle probability in itself is not a ground for 

 acceptance; and it is apparent that formulating conclusions on the 

 basis of probability is not a correct process according to the 3rd, 

 except in averaged results. With this exception, the process of for- 

 mulating probable conclusions rightly followed leads only to the most 

 probable conclusions, and these are not necessarily correct. It is the 

 essence of probability that its individual conclusions, including the 

 most probable, are a matter only of favorable as opposed to unfavor- 

 able chances. Such a conclusion may chance to be correct; but if so, 



