PHILOSOPHY IN THE NINETEENTH CENTURY 203 



nerves. This discovery was the contribution of the beginning of 

 the century to an entire line of discoveries, which have ended at the 

 close of the century with putting the localization of cerebral func- 

 tion upon a firm experimental basis. Of scarcely less importance 

 has been the cellular theory as applied (1838) by Matthias Schleiden, 

 a pupil of Fries in philosophy, to plants, and by Theodor Schwann 

 about the same time to animal organisms. To these must be added 

 the researches of Johannes Miiller (1801-1858), the great biologist, 

 a listener to Hegel's lectures, whose law of specific energies brings 

 him into connection with psychology and, through psychology, to 

 philosophy. Even more true is this of Helmholtz, whose Lehre von 

 den Toncmpfindungen (1862) and Physiologische Optik (1867) placed 

 him in even closer, though still mediate, relations to philosophy. 

 But perhaps especially Gustav Theodor Fechner (1801-1887), whose 

 researches in psycho-physics laid the foundations of whatever, either 

 as psychology or as philosophy, goes under this name; and whether 

 the doctrine have reference to the relation of man's mind and body, 

 or to the wider relations of spirit and matter. 



In my judgment it cannot be affirmed that the attempts of the 

 latter half of the nineteenth century to develop an experimental 

 science of psychology in independence of philosophical criticism and 

 metaphysical assumption, or the claims of this science to have 

 thrown any wholly new light upon the statement, or upon the 

 solution of philosophical problems, have been largely successful. 

 But certain more definitely psychological questions have been to 

 a commendable degree better analyzed and elucidated; the new 

 experimental methods, where confined within their legitimate 

 sphere, have been amply justified; and certain ^wast-metaphysical 

 views respecting the nature of the human mind, and even, if you 

 will, the nature of the Spirit in general have been placed in a 

 more favorable and scientifically engaging attitude toward speculat- 

 ive philosophy. This seems to me to be especially true with respect 

 to two problems in which both empirical psychology and philosophy 

 have a common and profound interest. These are (1) the complex 

 synthesis of mental functions involved in every act of true cogni- 

 tion, together with the bearing which the psychology of cognition 

 has upon epistemological problems; and (2) the yet more complex 

 and profound analysis, from the psychological point of view, of what 

 it is to be a self-conscious and self-determining Will, a true Self, 

 together with the bearing which the psychology of selfhood has 

 upon all the problems of ethics, aesthetics, and religion. 



The more obvious and easily traceable influences which have 

 operated to incite and direct the philosophical development of the 

 nineteenth century are, of course, dependent upon the teachings and 

 writings of philosophers, and the schools of philosophy which they 



