352 ANIMAL NATURE AS A WHOLE. [in. 



develop the same series of subordinate or single processes, pro- 

 duced by the other impressions necessary to the preservation of 

 the animal and the attainment of nature's objects ; and with 

 the same partly necessary and natural and partly incidental 

 co-ordination (696). All this takes place, in order that these 

 processes may be caused also at the same time by sensation, 

 perception, volition, effort, desire, aversion, reflection, and choice 

 and satisfaction of the animal, and thus it be rendered more 

 perfect, and capable of a more independent carrying out of its 

 proper objects (370, 371). 



699. The doctrine, as to the general subordination of all 

 animal forces to the primary vital force of the brain, may excite 

 doubts which require a solution. In this entire work, we have 

 taught that the most essential and the greater proportion of the 

 animal processes necessary to life, may go on perfectly, even in 

 sentient animals, not only absolutely, but also in their natural 

 connection, without the assistance or co-operation of the brain ; 

 and that it is possible animals may and do exist, that have 

 neither brain nor head, nor conceptive force, and yet can 

 perfectly perform all the functions necessary to their animal 

 life, by means of the vis nervosa only. How can t)iis agree 

 with the doctrine, that the brain is the centre of all the animal 

 forces of animals ? and that the secretion of vital spirits in it, 

 and their circulation through the whole system of animal 

 machines, is a primary vital force of all (675)? The animal 

 machine which secretes the vital spirits, is not in all animals 

 the same as that which is capable of animal-sentient forces, 

 although the term brain has been applied to both kinds (673). 

 All animal functions require the primary vital force of the 

 brain, because it is necessary to the secretion and transmis- 

 sion through the nerves of the vital spirits ; but all do not 

 require the animal-sentient forces, inasmuch as they can be 

 replaced by the vis nervosa only. In those animals not en- 

 dowed with animal-sentient forces, the secretion and diffusion 

 of the vital spirits is necessary to their animal processes ; and, 

 consequently, a brain endowed with a primary vital force is also 

 necessary, since all the processes are subordinate to it (680, 

 690). But this brain may be diffused throughout the body, and 

 every part may have its own brain ; and their animal processes 

 may be in subordination to the primary vital force of this 



