THE UNITY OF KNOWLEDGE 93 



When after the first third of the nineteenth century the great 

 philosophic movement which found its climax in Hegelianism came 

 to disaster in consequence of its absurd neglect of hard solid facts, the 

 era of naturalism began its triumph with contempt for all philosophy 

 and for all deeper unity. Idealism and philosophy were stigmatized as 

 the enemies of true science and natural science had its great day. The 

 rapid progress of physics and chemistry fascinated the world and pro- 

 duced modern technique; the sciences of life, physiology, biology, 

 medicine, followed; and the scientific method was carried over from 

 body to mind, and gave us at the end of the nineteenth century mod- 

 ern psychology and sociology. The lifeless and the living, the physical 

 and the mental, the individual and the social, all had been conquered 

 by analytical methods. But just when the climax was reached and all 

 had been analyzed and explained, the time was ripe for disillusion, 

 and the lack of deeper unity began to be felt with alarm in every 

 quarter. For seventy years there had been nowhere so much philo- 

 sophizing going on as suddenly sprung up among the scientists of 

 the last decade. The physicists and the mathematicians, the chemists 

 and the biologists, the geologists and the astronomers, and, on the 

 other side, the historians and the economists, the psychologists and 

 the sociologists, the jurists and the theologians all suddenly found 

 themselves again in the midst of discussions on fundamental princi- 

 ples and methods, on general categories and conditions of knowledge, 

 in short, in the midst of the despised philosophy. And with those 

 discussions has come the demand for correlation. Everywhere have 

 arisen leaders who have brought unconnected sciences together and 

 emphasized the unity of large divisions. The time seems to have come 

 again when the wave of naturalism and realism is ebbing, and a new 

 idealistic philosophical tide is swelling, just as they have always alter- 

 nated in the civilization of two thousand years. 



No one dreams, of course, that the great synthetic apperception, for 

 which our modern time seems ripe, will come through the delivery of 

 some hundred addresses, or the discussions of some hundred audiences. 

 An ultimate unity demands the gigantic thought of a single genius, 

 and the work of the many can, after all, be merely the preparation 

 for the final work of the one. And yet history shows that the one will 

 never come if the many have not done their share. What is needed 

 is to fill the sciences of our time with the growing consciousness of 

 belonging together, with the longing for fundamental principles, with 

 the conviction that the desire for correlation is not the fancy of 

 dreamers, but the immediate need of the leaders of thought. And in 

 this preparatory work the St. Louis Congress of Arts and Science 

 seemed indeed called for an important part when it was committed 

 to this topic of correlation. 



To call the scholars of the world together for concerted action 



