490 PSYCHOLOGY. 



may liave its data written tlown in an evenly gradated order, 

 from a loAvest to a highest nieniLer. And any one datum 

 may be a term in several such orders. A given note may 

 have a high place in the pitch-series, a low place in the 

 loudness-series, and a medium place in the series of agree- 

 ablenesses. A given tint must, in order to be fully deter- 

 mined, have its place assigned in the series of qualities, in 

 the series of jjurities (freedom from white), and in the series 

 of intensities or brightnesses. It may be low in one of 

 these respects, but high in another. In passing from term 

 to term in any such series we are conscious not only of each 

 step of difi'erence being equal to (or greater or less than) 

 the last, but we are conscious of proceeding in a urtiform 

 direction, diflerent from other possible directions. This 

 consciousness of serial increase of differences is one of the 

 fundamental facts of our intellectual life. More, more, 

 MoiiE, of the same kind of difference, we say, as we advance 

 from term to term, and realize that the farther on we get 

 the larger grows the breach between the term we are at 

 and the one from which we started Between any two 

 terms of such a series the difference is greater than that be- 

 tween any intermediate terms, or than that between an inter- 

 mediate term and either of the extremes. The louder than 

 the loud is louder than the less loud ; the farther than the 

 far is farther than the less far ; the earlier than the early is 

 earlier than the late ; the higher than the high is higher 

 than the low ; the bigger than the big is bigger than the 

 small ; or, to put it briefly and universally, the more than the 

 more is more than the less ; such is the gi^ecd synthetic prin- 

 ciple of mediate comparison which is involved in the posses- 

 sion by the human mind of the sense of sericd increase. In 

 Chapter XXVIII we shall see the altogether overwhelming 

 importance of this principle in the conduct of all our higher 

 rational operations. 



ABE ALL DIFFERENCES DIFFERENCES OF COMPOSITION? 



Each of the differences in one of these uniform series 

 feels like a definite sensible quantity, and each term seems 

 like the last term with this quantity added. In many con- 

 crete objects which differ from one another we can plainly 



