508 



SCIENTIFIC THOUGHT. 



29. 



Lotze's 

 "local 

 signs." 



30. 



Pechner. 



that of localisation of things in space. Lotze was one of 

 the first to attempt detailed answers to these questions. 

 In particular he propounded the theory of " local signs," 

 which with certain modifications has been adopted by 

 subsequent writers on the subject. The combination 

 of physiological, optical, and psychological investigations 

 in Helmholtz's great work on ' Physiological Optics ' 

 has brought definiteness and mathematical precision 

 into many of the questions suggested by philosophers 

 and naturalists before him. Through it and its great 

 companion, the ' Physiological Acoustics,' psycho-physics 

 has to a large extent become an exact science. 



A great step in the direction of drawing psychical 

 phenomena into the circle of the exact sciences was taken 

 independently by Gustav Theodor Fechner ; l in fact, it is 



1 G. T. Fechner (1801-1887) was 

 a unique figure in German liter- 

 ature, science, and philosophy. 

 Beyond his own country he is only 

 very imperfectly known and appre- 

 ciated. He was self-taught, and 

 living all his life somewhat outside 

 the conventional categories of Ger- 

 man academic activity, he made 

 a position for himself which has 

 only become intelligible to a larger 

 public through the issue after 

 his death of Prof. "Wundt's ora- 

 tion, Prof. Kuntze's (his nephew's) 

 charming biography (1892), and 

 Prof. Lasswitz's monograph on 

 Fechner (Stuttgart, 1896), in 

 which for the first time a co- 

 herent exposition of his philo- 

 sophical teaching is attempted. 

 Prof. Wundt has also, in many 

 passages of his work on psy- 

 chology, and through the second 

 edition of the ' Psychophysik,' con- 

 tributed largely to a better under- 

 standing of Fechner's views and 

 merits. He descended on both 



sides from ancestors whose position 

 was that of highly esteemed Pro- 

 testant pastors ; he studied medi- 

 cine like Lotze, and was the friend 

 and colleague of Lotze's teachers, 

 Weber and Weisse. In his auto- 

 biographical record, communicated 

 by Kuntze, he confesses having be- 

 come almost an atheist under the 

 influence of his medical studies, 

 until he became acquainted with 

 the philosophy of Schelling, Oken, 

 and Steffens, which dazzled him, 

 touched the poetical and mystical 

 side of his nature, and, though he 

 hardly understood it, had a lasting 

 influence on him. The simultan- 

 eous occupation with the best 

 scientific literature of the day (he 

 translated French text-books such 

 as those of Biot and Thenard, and 

 verified Ohm's law experimentally), 

 however, forced upon him the scep- 

 tical reflection whether, "of all 

 the beautiful orderly connection 

 of optical phenomena, so clearly 

 expounded by Biot, anything could 



