256 E. E. FREE 



out of the process except what goes in. It is impossible to lay 

 too much stress upon this limitation, for the apparently quantita- 

 tive expressions derived by this method are likely to seem more 

 valid than they are and to blind the user to their absolute de- 

 pendence upon the individual judgments from which they are 

 built up. From all of this it follows that the method is valuable 

 only when correct judgment is possible which means, usually, 

 criteria of difference which are definitely understood and appreci- 

 ated, the possibility of simultaneous comparison, and a series 

 the differences within which are not so wide as to confuse and 

 hamper the individual judgments. 



