412 INTRODUCTION TO PHILOSOPHY OF SCIENCE 



the results of discovery, beginning with digests, and going 

 on to the endeavor to form a philosophy of science. Such is 

 the nature of Humboldt's Cosmos, of Comte's Philosophie 

 positive, and of Spencer's Synthetic Philosophy. The classifi- 

 cation of the sciences belongs to this department." * Hence 

 Peirce might himself label his classification of the sciences 

 by calling it an instance of a science of review. Peirce does 

 not tell us what he means by his third great division — 

 practical science. In this, as in the case of sciences of review, 

 he offers not a classification but illustrations. He finds 

 himself somewhat bewildered by the motley crowd of prac- 

 tical sciences, but comforts himself in the belief that the 

 classification of this branch is of no logical importance. 



BLISS 



The basic principle which Bliss employs is that of grada- 

 tion by speciality. "It may be comprehensively defined as 

 the principle by which the several sciences and studies, dis- 

 tinguished by their conceptual scope and their relations to the 

 real order of nature, are arranged in serial order from the most 

 general to the most special. . . . The generalizations and 

 laws of each more general science are true in some measure 

 of all the more special sciences. . . . But the laws or truths 

 of the more special sciences rarely apply to the more general 

 sciences or solve their problems. The special sciences, how- 

 ever, supply materials to which the generalizations and laws 

 of the more general sciences are generally applicable, and 

 by which they may be verified. Here are involved the 

 principles of the dependence of the special sciences on the 

 general, the interdependence of the several sciences, general 

 and special, and filiation of the more special sciences in suc- 

 cessive derivation from and dependence upon the more 

 general." 2 



Combined with the principle of gradation by speciality, 

 however, there is a further principle. It permits the four- 

 fold division of studies into philosophy, science, history, and 



1 Ibid., par. 1.182. 2 H. E. Bliss, op. cit, pp. 217-218. 



