338 The Unity of the Organism 



the subtler aspects of the problem. The little we shall do 

 in this way may be introduced by the query, what reason 

 is there for including in our hypothesis the supposition that 

 it is "some substance in the air, almost certainly oxygen," 

 with which the organism reacts chemically, to produce con- 

 sciousness and all other phenomena of life? Why single out 

 this substance from the other elementary substances essential 

 to life, as for instance carbon or nitrogen? * My reply be- 

 gins by recalling the immemorial recognition of the "breath 

 of life" the "life giving air" and so on, of universal experi- 

 ence. It is well to recall likewise such semi-philosophic con- 

 ceptions as that of the pneuma or "psychical breath of life" 

 of later Greco-Roman philosophy. The inextricable en- 

 tanglement, historically, of breath and air with spirits is 

 also worth remembering, especially the continuance of this 

 into the modern period of scientific analysis, unmistakeable 

 traces of which are seen in the writings of William Harvey 

 and the foremost physiologists of the era to which he be- 

 longed. For example, the spiritus nitro-aereus of John 

 Mayow which, we now know, was his term for oxygen as 

 glimpsed first in the history of science, may be mentioned. 



More important than any of these reminders from the his- 

 tory of knowledge is that of the familiar fact that the most 

 crucial evidences of truly independent or autonomous life of 

 the individual higher animal are respiratory. That the new 

 born human babe's first breathing-act is its first genuine in- 

 dependent life-act is one of the most commonplace of truths. 

 And recall how the "return of life" as we say of the nearly 

 drowned person, and of one who has "fainted dead away" 

 is marked by the resumption of respiratory activities. Cer- 

 tain reflexes, as those from stimulating the eyelids, and pos- 



* The argument in answer to this query should be taken as an exten- 

 sion of, and in important respects a replacement of, that contained in 

 my essay, Is nature infinite? 3 ' 7 wherein I discuss the specificity of in- 

 dividual organisms as indicated by how they use their nutrient sub- 

 stances. 



