THE RELATIONS OF PSYCHOLOGY 631 



division or slackness are not to be the results. Isolated and sporadic 

 phenomena are always setting mental energy a task. 



The conception of mental energy can, as all conceptions of energy, 

 only be defined by the labor which is performed, the resistance which 

 is conquered. There is so much more mental labor to be performed, 

 the more elements or tendencies there are that have to be united in 

 the same mental state, the more different these elements or tend- 

 encies are, the stronger each of them is, the more intimately they 

 are to be united, and the more remote in time they are from one 

 another and from the present moment. It is true that in the indi- 

 vidual cases it will be a matter of no little difficulty to apply that 

 concept of psychical energy, whose possibility does here appear. The 

 five factors of psychical energy can only be determined by careful 

 observation and all-sided knowledge of the special historical and 

 individual conditions in each single case. The number of elements 

 or tendencies, the degree of their difference, the intensity of each 

 one of them, the intimacy of their connection, the degrees of their 

 distance in time, all this it is difficult to point out with certainty, 

 and it varies from case to case. And to all this is yet to be added 

 the velocity with which the mental functions of synthesis is to be 

 performed. We have not here such simple factors as mass and 

 velocity, by which physical energy is determined. 



An inexhaustible wealth of possibilities is conditioned by the 

 very different ways and degrees in which these five separate cir- 

 cumstances may appear. There is here a great field for observation, 

 experiment, and comparison. The comparative psychology of indi- 

 viduality is as yet in an elementary state. Only in the domain of 

 psychology of religion, especially here in America, a movement has 

 begun in this direction. But no theory can ever give an exhaustive 

 description of the manner in which the different elements or tend- 

 encies work together in any single state of a single individual. 

 Here, as everywhere, the perfect individualization is to be attained 

 by art, not by science. Art only can give a synthesis, which in some 

 measure can do justice to the great synthesis of life. 



Ill 



New problems arise when we try to characterize the relation of 

 psychology to its neighboring sciences. Psychology has a special 

 relation, on one side to physical, and on the other side to historical 

 and ethical science. And the relation can be shortly said to be that 

 in comparison with physical science psychology has a decidedly syn- 

 thetic character, but in comparison with historical and ethical science 

 a decidedly analytical character. By these contrasts the problems 

 which arise at the limits of the different sciences are determined. 



