xxviii EDITOR'S INTRODUCTION 



Aristotle and Linnaeus to taxonomy. In the modem period Agassiz 

 applauded the labors of taxonomists like Cuvier and von Baer, who 

 understood that "there is no such uniformity or regular serial gTada- 

 tion among animals." Since categories of thought were mutually 

 exclusive with no genetic connection possible among the four great 

 branches of the animal kingdom, it followed that the "plan of 

 structure" of each was "so peculiar that we nowhere find analogies 

 . . . extending from one branch to all the representatives of another 

 branch." No system of classification that suggested such relationship 

 could be "true to nature." 



This discontinuous view of creation underscored Agassiz's entire 

 conception of natural history and philosophy. Within the frame- 

 work of its logic it was possible to ascribe tremendous if capricious 

 power to the Creator, who was given responsibility for the origin 

 of life and for all subsequent alterations. In one example after an- 

 other Agassiz used this logic to refute notions of physical unity and 

 genetic affiliation. Animals and plants of ancient times and of the 

 present were viewed as the result of independent creative acts, their 

 life history always subject to divine intervention in the form of 

 catastrophes. Animals that remained unchanged after long periods 

 of time demonstrated the wisdom of the plan; those that were ex- 

 tinct bore "prophetic" relationship to' their successors that proved 

 creative intent for the future. 



The evidence of creative force on earth was the individual animal 

 or plant. Each individual exemplified a species, a genus, a family, 

 and other higher and more inclusive orders of taxonomic identity. 

 Ideal categories never changed, so that it was impossible to speak, 

 as evolutionists did, of the "transmutation of species." Whereas 

 evolutionists thought of species as subjective creations of the natu- 

 ralist, Agassiz insisted on their ideal character, thus also denying their 

 biological reality but doing so from ultimate considerations. He 

 was therefore able to ask the perfectly logical question: "if species 

 do not exist at all, as the supporters of the transmutation theory 

 maintain, how can they vary? And if individuals alone exist, how 

 can the differences which may be observed among them prove the 

 variability of species?" ^*^ 



Agassiz was too careful an investigator to deny the fact of change 



^"American Journal of Science, XXX (2d ser., 1860), 143. 



