PAET I. 



ANIMAL NATURE IN ITS CONNECTION WITH 



THE SENTIENT FACULTY OF THE 



SOUL OF AN ANIMAL. 



CHAPTER I. 



I 



THE ANIMAL MACHINES IN GENERAL, AND ESPECIALLY AS THEY 

 ARE ADAPTED TO THE ANIMAL-SENTIENT FORCES. 



9. The proper animal macliines in animal organisms are the 

 brain and nerves/ in which the vital spirits (the nervous fluid) 

 are produced and distributed, with the object of constituting 

 the medium of the functions of these organs. 



10. The brain is the seat of the soul. We feel that we think 

 in the head ; nowhere else are we conscious of our existence ; 

 in no other organ is there a thought^ or an idea, or consci- 

 ousness. Now, since the sentient faculty [Vorstellungskraft^] 

 of animals is their soul, the soul can have its seat nowhere else 

 than in the brain, and it would be absurd to maintain that it 

 is diffused throughout the body (597). It is sufficient to a 

 physician to know, that the thinking faculty can have no other 

 seat than the medullary matter of the brain. 



11. The brain is the laboratory of the vital spirits (15, i). 

 " It appears certain that there is such a fluid essence secreted 



' As the phrase thierischen maschinen is used for the most part by Unzer to 

 indicate the nervous system, it is so translated throughout the work wherever the 

 context permits. — Ed. 



'•' The term VorstellungsJcraft is of very frequent occurrence, and has been trans- 

 lated by the terms sentient faculty or force, conceptive faculty or force, and simply 

 mind. — See note to $ 6, 25. — Ed. 



2 



