lo THE POPULAR SCIENCE MONTHLY 



volumes were thus made known, but from them it was impossible more 

 than to conjecture what the treatment would have been. The complete 

 scheme was drawn up early in 1858 and sent to his father in a letter, 

 but the revised scheme, issued in 1860, and with which we are all 

 familiar, wants the details for all below the biology. Not until the 

 *' Autobiography " appeared in 1904 was this hiatus supplied.^ This 

 was the reason for publishing a letter from him dated September 19, 

 1895, in which considerable was said on this subject. Nearly eight 

 years, however, were allowed to elapse before this step was taken in 

 1903. His permission to publish it would have been asked had it not 

 been known that at that date Mr. Spencer was nearing his end, his 

 death occurring in December of the same year, and it seemed highly 

 important that information so vital to his system should not be lost.^ 



While, therefore, Mr. Spencer's treatment of inorganic nature, so 

 far as it could be judged from " First Principles " and other indica- 

 tions, was full of promise, still, inasmuch as he did not fulfil that 

 promise by an exhaustive elaboration of it, it was soon overshadowed 

 by his work in the next great field, that of biology, the only other field 

 of his labors in which no early preconceptions existed to warp his 

 judgment or impede the flight of his genius. 



Herbert Spencer's " Principles of Biology " is the gem of his " Syn- 

 thetic Philosophy," and must rank for all time as his masterpiece. 

 In it he founds the science of biology squarely upon that of organic 

 chemistry, and " Chemical Development " was to have been the final 

 topic of " The Principles of Geogeny."^ This makes clear the filiation 

 of the sciences thus far. Then come his several proximate definitions 

 of life, closing with " the broadest and most complete " one : " the 

 continuous adjustment of internal relations to external relations." 

 Few have been satisfied with this, and the more it is studied the less it 

 seems to fulfil the conditions. The objection to it is that there is no 

 life in the definition. It is strange that he should have failed to 

 cement the lowest organic science, biology, to the highest inorganic 

 science, chemistry, by recognizing the brief step from the spontaneous 

 molecular activities of the most complex organic compounds, the albu- 

 minoids, to the no more spontaneous molar activities (motility) of the 

 simplest living substance, which we know as protoplasm, and believe 

 to result from the further recompounding of the former.^ 



" " Autobiography," Vol. II., p. 17; " Life and Letters," Vol. II., pp. 158-159. 



* " Pure Sociology," pp. 66-67. A portion of this letter appears in " Life 

 and Letters," Vol. II., pp. 90-91. Mr. Duncan should have mentioned this 

 earlier publication of the letter in full followed by the reply to it and a fur- 

 ther discussion of the principles involved. 



' " Life and Letters," Vol. II., p. 159. 



" Cf. " The Organic Compounds in their Relations to Life," Proc. A. A. 

 A. 8., Vol. XXXL, pp. 493-494; The American Naturalist, Vol. XVI., December, 

 1882, pp. 968-979. 



