L 2' ] 



meaning is that the same stimulus which acts on our 

 visual and tactile senses as a tremor, acts on our 

 auditory sense as a sound. In this scientific sense 

 the terms cause and effect simply denote a particular 

 mode of syntaxis. Similarly other forms of connec- 

 tion, such as time, space, matter, ether, and the like, 

 will be found on examination to indicate other 

 modes of syntaxis. 



Every conceivable connection among reminis- 

 cences, simply because it is conceivable, is a possible 

 syntax ; but evidently any one syntax is not as good 

 as any other ; the whole problem of science turns on 

 the distinctions between them. For centuries past 

 the question has been discussed : What criterion 

 should be applied to distinguish a good syntax from 

 a worthless one, or, as it is generally expressed, a 

 true proposition from a false one ? Instead of 

 attempting a direct answer, what I propose to do 

 here is to consider a somewhat different question, 

 namely : What is the criterion which, as a matter 

 of history, has been applied in science to distinguish 

 truth from error ? 



In analysing the history of science with a view 

 to isolating such a criterion, it is important to notice 

 that the syntaxes of science have not been immutable, 

 but that a syntax which has been accepted at one 

 period as true, has often been rejected at a later 

 period. If we find then, that all syntaxes are 

 accepted when they possess a certain characteristic, 



