358 ZOOLOGICAL PHILOSOPHY 



the new action is purely a sequence of some emotion of their inner 

 feehng. 



It is therefore only the animals which, in addition to a nervous 

 system, possess the special organ for complex ideas, thoughts, com- 

 parisons, judgments, etc., that possess the faculty of will and can carry 

 out acts of will. This apparently is the case with the vertebrates : 

 and since the fishes and reptiles have so imperfect a brain as not com- 

 pletely to fill up the cranial cavity^an indication that their acts of 

 intelhgence are extremely limited — it is mainly in the birds and 

 mammals that the faculty of will is to be found ; for they obviously 

 carry out various acts of intelligence, and certainly have the special 

 organ which renders them capable of such acts. 



But as I have already observed : in the case of animals which have a 

 special organ for intelhgence, all the actions do not result exclusively 

 from a will, that is, from a prehminary intellectual determination 

 which excites the motive power of actions. Some of them are no doubt 

 the product of the faculty of will, but many others simply arise from a 

 direct emotion of the inner feehng, which is excited by sudden needs and 

 causes the animal to carry out actions that are not preceded by any 

 determination or thought. 



Even in man, how many actions there are that are exclusively 

 prompted and carried out by an emotion of the inner feeUng, without 

 any intervention of the will ! Do not many of our actions owe their 

 origin to instantaneous and uncontrolled movements ; and what are 

 these movements but results of the inner feehng ? 



If, as I said above, there is no true will in animals which have a 

 nervous system without any organ for intelligence, and if this is the 

 reason why such animals only act by emotions produced by their 

 sensations, this truth applies still more to animals that have no 

 nerves. It appears therefore that these latter only move by an 

 excited irritability, and as an immediate result of external excitations. 



It is easy to imagine from the above exposition that, after nature 

 had transferred the power of acting into the interior of animals, that 

 is, after she had created the inner feehng based on the nervous system 

 as the origin of the force for producing actions, she then perfected 

 her work by creating a second internal power, that, viz. of the will, 

 which arises from acts of intelligence and is the only faculty that can 

 cause any variation in the habitual actions. 



For this purpose, nature was obliged to add a new organ to the 

 nervous system, in which acts of intelligence might be carried on ; 

 and she had to separate the nucleus of sensations or perceptions from 

 the organ of ideas, comparisons, judgments, reasonings, thoughts. 



Thus in the most perfect animals the spinal cord provides for the 



