SECTION IV. 



IF it be admitted that a scientific syntax, in order 

 to be satisfactory, must include all the reminiscences 

 which can be brought together, relating to the 

 matter in hand, it is evident that a place must be 

 found among the rest for reminiscences of infor- 

 mation obtained from the evidence of others ; hence 

 it will not be inappropriate to illustrate the use of 

 the scientific criterion by showing its application to 

 the question of the truth of evidence. We are some- 

 times told that evidence should be accepted or re- 

 jected, according to its probability ; but in the 

 absence of any criterion of probability, the phrase 

 affords no guidance, since the estimation of the 

 probability of the evidence is nothing else than the 

 formation of an opinion as to its truth ; the two 

 expressions merely describe the same process in 

 different words. The question whether a particular 

 piece of evidence is trustworthy, and if so, to what 

 extent that is to say, the question of the weighi 

 of that evidence is in its own way a minor scientific 

 problem, and the only reasonable method of dealing 

 witli it is to use the same criterion which I have 

 shown to be applicable to other problems. Just as 

 the criterion has long been practically applied to 

 these, so it has also been applied to questions of 



