THE DOCTRINE OF VITAL UNITY. 149 



The Doctrine of the Vital Duality of Animals and 

 Plants. There are, therefore, biologists who, in the 

 domain of theory and in virtue of more or less well- 

 founded conceptions or interpretations, separate 

 elementary life from other vital forms, and thus break 

 the bond of vital unity proclaimed by Claude Bernard. 

 This monistic doctrine at the outset met with other 

 opponents, and that, too, in the domain of facts. 

 But it triumphed over them and became established. 

 We have to deal with scientists like J. B. Dumas and 

 Boussingault, who drew a dividing line between 

 animal life and vegetable life. 



But let us in a few words recall to the reader this 

 victorious struggle of the monistic doctrine against 

 the dualism of the two kingdoms. If we consider an 

 animal in action, said the champions of vital dualism, 

 we agree that it feels, moves, breathes, digests, and 

 finally, that it destroys by a real operation of chemical 

 analysis the materials afforded to it by its ambient 

 world. It is in these phenomena that are manifested 

 its activity, its life. Now, added the dualists, plants 

 do not feel, do not move, do not breathe, and do not 

 digest. They build up from immediate principles, 

 by an operation of chemical synthesis, the materials 

 they borrow from the soil which bears them, or from 

 the atmosphere which surrounds them. There is, 

 therefore, nothing in common between the repre- 

 sentatives of the two kingdoms if we confine ourselves 

 to the examination of the actual phenomena which 

 take place in them. To find a resemblance between 

 the animal and the vegetable, said the dualists, we 

 must set aside what they do, for they do different, or 

 even contrary things. We must consider whence 

 they come and what they become. Both originate 



