560 THE ROYAL SOCIETY OF CANADA 



expediency, because the originator of a truly great hypothesis is 

 its natural, and usually its most successful, investigator. If an 

 hypothesis be of great, and especially of practical, importance, and the 

 scientist for any reason is not in a position to complete the investiga- 

 tion, he may be justified in printing the useful part of his data, if at 

 the same time he eschews the part of an advocate, and instead points 

 out frankly the gaps in the proof which will need to be filled by subse- 

 quent investigators. In history the need for any such doubtful ex- 

 pedients does not arise. The historian fulfils the requirements of his 

 science by preparing a narrative of necessary conclusions, and the 

 publicity given to probable conclusions and hypotheses under the pre- 

 vailing historical method is not for the sake of further investigation 

 by other historians, but with a view to acceptance by readers and 

 hearers. 



A systematic generalization explaining without exception an en- 

 tire group of ascertained, related facts is entitled to publicity, though 

 it be only a probable explanation of those facts. Such generalizations 

 are known as theories and are accepted only provisionally, i.e., so 

 long as no additional fact be discovered which the theory fails to explain. 

 If such a case arises, the theory as a whole is abandoned unless 

 the fact can be differentiated, i.e., unless the theory can be so restated 

 that the additional fact ceases to be an exception and is brought within 

 the modified theoretical law. (This procedure corresponds with the 

 4th methodic principle in dealing with a failure in a process hitherto 

 considered to have been established by experience as correct. An 

 erratic or undifferentiated exception to the theory, like an erratic or 

 undifferentiated failure of the process, condemns the theory or process 

 as a whole.) 



Historical science does not admit of any such systematic generali- 

 zations. 



It is the disregard of the above principles concerning the degree of 

 publicity rightfully allowed to probable conclusions that has brought 

 upon science the reproach, in so far as such reproach is deserved, 

 that "the science of one generation is the ignorance of the next," and 

 her past is only a "cemetery of exploded beliefs." If probability be 

 confined to its proper function, and probable conclusions receive only 

 their proper degree of publicity, this reproach will cease, and instead 

 there will be a gradual increase of ascertained facts, and a correction of 

 the incidental errors which are an unavoidable but on the whole unim- 

 portant feature in the essentially correct results afforded by correct 

 processes; while in those branches of science susceptible of systematic 

 generalizations, there will be a gradual perfecting of these theories 

 until all the related facts are ascertained and brought within the theo- 

 retical laws. 



