i4o POPULAR SCIENCE MONTHLY 



compelled to make contrary movements. Thus the same thread runs through 

 all material phenomena. The human mind is nothing but the highest develop- 

 ment on our earth of the mental processes which universally animate and move 

 nature. 13 



Fechner had worked out this fundamental theory ere he arrived at 

 his psychological results. We find glimmerings of it so soon as 1835, 

 in the attractive " Little Book on Life After Death," in the tract " On 

 the Highest Good" (1846) ; enlarged views in " Nanna, or the Soul- 

 life of Plants" (1848); while the system appears full-fledged in 

 "Zend-Avesta, or the Things of Heaven and the Hereafter" (1851) ; 

 in 1861 he returned to it in his book, " On the Soul Question," occa- 

 sioned by contemporary materialism, and in " The Three Motives and 

 Grounds of Belief "; and in 1879 he reaffirmed and restated the position 

 in the remarkable volume entitled " The Day View and the Night 

 View." The essence of his teaching may be summed up in the thought 

 that the material or external world is a half-truth, a concession to the 

 sensuous, rather than an explanation of the psychical; 



However complicated our brains may be, and however much we may feel in- 

 clined to attach to such a complexity the highest mental properties, the world 

 is unspeakably more complex, since it is a complication of all the complications 

 contained in it, the brains among them. Why not, therefore, attach still higher 

 mental properties to this greater complexity? The form and structure of the 

 heavens seem simple only when we consider the large masses and not their 

 details and concatenation. The heavenly bodies are not crude homogeneous 

 lumps; and the most diverse and complicated relations of light and gravity 

 obtain between them. That, however, the plurality in the world is also grouped, 

 comprehended, and organized into unity does not contradict the thought that it 

 is also comprehended into a corresponding mental unity, but is in harmony with 

 the same. 14 



Consequently, the physical symbolizes the psychical. They are two 

 faces of a single existence. Human research may, therefore, deal with 

 the one or the other, and attain, as it has attained, great success. But 

 the real problem centers in the relation between the two. Of this, 

 physiological psychology is the science. You can, accordingly, pursue 

 it qua science, but you must never forget the larger setting in which 

 it finds itself. 



Proceeding to the psychology, then, note at once that Fechner en- 

 visages the problem rather as a physicist than as a physiologist. So, 

 he suffers from his limitations, but gains in precision. Soul and body 

 being a single existence, it is practicable to investigate their mutual 

 functioning and to state the results as laws of nature, which, in turn, 

 are no more than assemblages of observations concerning phenomenal 



13 Cf. " Die mechanische-physiologische Theorie d. Abstammungslehre " 

 (1884). 



" " Ideen zu einer Schopfungsgeschichte," p. 106. 



