46 THE POPULAR SCIENCE MONTHLY 



systematic philosophy of the time, even as its source — tlie deeply reli- 

 gious turn of Fechner's nature had little place among the conventional 

 philosophizing motives. 



Incidentally it may be said that the publication of Fechner of a 

 little volume of riddles in rhythm for children between the appearance 

 of the " Zend Avesta " and the work on the plant soul may throw some 

 light on the failure of the professorial absolute idealist to understand 

 the nature of the versatile founder of the " Philosophic von TJnten." 



But the year 1848 was a very unfavorable one in Germany for the 

 reception of a new philosophy, particularly for a philosophy to which 

 it was so tempting to attach the tag of mysticism. The German folk, 

 wearied with the pretensions and dialectics of the rationalistic philos- 

 ophers, aroused by vital questions of constitutional government and 

 interested in the vigorous growth of natural science, had no time to 

 waste on such questions as the mentality of plants and planets; the 

 shallow materialism of Vogt and Biichner seemed to fall in easily with 

 current theories of physical science; as a verbal proposition it seemed 

 much easier to understand the statement that the brain secretes thought 

 as the liver secretes bile, than to work out Fechner's involved, if keen, 

 reason in regard to the seat of the soul. And so the "Zend Avesta" 

 rested quietly with the " Nana " on the book shelves of the publishers. 

 But in no wise discouraged, Fechner once more attacked the question of 

 the parallelism of soul and body as a special problem " von unten auf," 

 and in 1859 published the famous treatise on psychophysics. 



The motive for this work was to determine, if possible, exact rela- 

 tions existing between the mental acts, the "psyche," and the accom- 

 panying physical process, or, in short, to determine quantitative rela- 

 tions existing between mind and body. Considering the general disbe- 

 lief in regard to the possibility of such determinations, which had been 

 summed up by Kant in the dictum that psychology could never be- 

 come a science because it could never be treated mathematically, Fech- 

 ner's plan might reasonably be termed bold. But when one thinks of 

 the practical difficulties of the undertaking that Fechner had to create 

 new scientific concepts and name them, that he had to create and de- 

 velop totally new methods of investigation and tliat he had to invent 

 new apparatus or apply old to totally new uses, it miglit seem as if 

 Fechner had passed from the region of the improbable to that of the 

 impossible. 



The occasion for the psychophysics was a simple investigation on 

 our discriminative sensibility for lines and weights, made by the physi- 

 ologist E. H. Weber, one of the "seven sages of Gottingen." Weber 

 simply states that we have the power to distinguish between tlie lengths 

 of two lines which are to each other as 39 to 40 and between weights witli 

 a ratio of 20 to 30. Moreover, these ratios are general, holding for centi- 



