THE DEVELOPMENT OF CLASSIFICATION 101 



sent a world of phenomena which in its nature is absolutely different 

 from that of material phenomena, and, while it is true that every 

 ethical action and every logical thought can, from the standpoint of 

 the biologist, be considered as a property of matter, it is not less true 

 that the sciences of mental phenomena, considered impartially, form 

 a sphere of knowledge closed in itself, and must thus be coordinated, 

 not subordinated, to the knowledge of the physical world. We should 

 say thus: all knowledge falls into two classes, the physical sciences 

 and the mental sciences. In the circle of physical sciences we have the 

 general sciences, like physics and chemistry, the particular sciences of 

 special objects, like astronomy, geology, mineralogy, biology, and the 

 formal sciences, like mathematics. In the circle of mental sciences we 

 have correspondingly, as a general science, psychology, and as the 

 particular sciences all those special mental and moral sciences which 

 deal with man's inner life, like history or jurisprudence, logic or ethics, 

 and all the rest. Such a classification, which had its philosophical 

 defenders about twenty years ago, penetrated the popular thought 

 as fully as the positivism of the foregoing generation, and was cer- 

 tainly superior to its materialistic forerunner. 



Of course it was not the first time in the history of civilization that 

 materialism was replaced by dualism, that biologism was replaced by 

 psychologism ; and it was also not the first time that the development 

 of civilization led again beyond this point: that is, led beyond the 

 psychologizing period. There is no doubt that our time presses 

 on, with all its powerful internal energies, away from this Weltan- 

 schauung of yesterday. The materialism was anti-philosophic, the 

 psychological dualism was unphilosophic. To-day the philosophical 

 movement has set in. The one-sidedness of the nineteenth century 

 creed is felt in the deeper thought all over the world : popular move- 

 ments and scholarly efforts alike show the signs of a coming idealism, 

 which has something better and deeper to say than merely that our 

 life is a series of causal phenomena. Our time longs for a new inter- 

 pretation of reality; from the depths of every science wherein for 

 decades philosophizing was despised, the best scholars turn again to a 

 discussion of fundamental conceptions and general principles. Histor- 

 ical thinking begins again to take the leadership which for half a cen- 

 tury belonged to naturalistic thinking; specialistic research demands 

 increasingly from day to day the readjustment toward higher unities, 

 and the technical progress which charmed the world becomes more 

 and more simply a factor in an ideal progress. The appearance of this 

 unifying congress itself is merely one of a thousand symptoms of 

 this change appearing in our public life, and if the scientific philo- 

 sophy is producing to-day book upon book to prove that the world 

 of phenomena must be supplemented by the world of values, that 

 description must yield to interpretation, and that explanation must 



