[ 22 ] 



but are rejected when they possess it no longer, the 

 inference will be that this characteristic is the one 

 criterion by which the valuable syntax has been 

 distinguished from the useless ; the true from the 

 erroneous. 



My whole object here is to show that this criterion 

 corresponds to the formula given in the heading of 

 the paper, namely : When a logical arrangement of a 

 whole class of reminiscences affords a mental picture 

 of relationship among them, clearer, more direct and 

 better adapted for complete mental comprehension 

 than any arrangement previously suggested, then that 

 arrangement is accepted as a basis of scientific truth, 

 and the relationship involved therein is held to be a 

 true nexus. 



To prove the universal use of this criterion it 

 would be necessary to go through the whole history 

 of every branch of science, which is manifestly 

 impossible ; all that can be done here is to give a 

 few illustrations of its use ; and in doing this it will 

 be best to take our examples from the older branches 

 of science, because these have had a longer time for 

 their development, have passed through more changes, 

 and have produced results which are now more 

 universally recognised than those of the more recent 

 branches. Turning then to astronomy, the oldest of 

 them all, we find that the earliest syntax relating to 

 the motions of the heavenly bodies was animistic; 

 that is to say, men, observing these motions, compared 



