272 The Older Doctrines [lect. 



the part residing in the brain and nervous system was of the 

 nature of ' light.' This is what, in his rhetorical way, he says : 



" The corporeal soul common to man and the higher animals, 

 "while it extends over the whole organic body and vivifies, 

 " actuates and irradiates every part, both tissues and humours, 

 "yet seems more eminently to subsist in two of these, and 

 " to hold them as its imperial seats as it were. These subjects 

 "of the soul are on the one hand the vital fluid, the blood, 

 "circulated in a perpetual round in the heart, arteries and 

 "veins, and on the other the animal fluid or nervous juice 

 " streaming gently through the brain and its belongings. Both 

 " these provinces the soul inhabits and adorns with its presence, 

 " but since the whole soul cannot be in both provinces at the 

 " same time, it is as it were divided, it actuates each province 

 " by its appropriate half. One of its halves, since it is as we 

 " have shewn of the nature of fire, glides into the blood after 

 " the fashion of a lighted flame, while the other half seems 

 "diffused through the animal fluid after the manner of light, 

 "like the rays of light emanating from that flame, rays which, 

 "taken up by the brain and the nerves as by dioptic glasses 

 "and manifoldly reflected or refracted, form various figures 

 " according to the workings of the animal faculties. 



" The animal soul therefore, corresponding to its dual chief 

 " functions in the animal body, consists of two distinct parts, 

 " namely, flame and light ; for as regards the functions called 

 " natural, these are in truth only involuntary animal functions 

 " and are carried out by the aid of animal spirits." 



He devotes a special treatise to prove that the blood 

 is aflame, is burning, that a flame exists in the blood. 

 He had, as I have said, many sound physiological views. 

 He says of the blood : " The functions of the blood at 

 "least in the higher animals are diverse and manifold. 

 "It instils into the brain and nervous system materials 

 "for the animal spirits, it provides nutritive juice for the 

 "various tissues, it supplies the elastic link to the motor 

 " structures, and besides secretes various residues and effete 

 "particles, and deposits them in the appropriate emunc- 

 " tories." Nor can even modern physiology find fault with 



