384 ZOOLOGICAL PHILOSOPHY 



exerting the intellect, when the circumstances of life are favourable, 

 enables a man to extend his knowledge, to enlarge and guide his genius, 

 in short, to see things on a large scale, to embrace in thought almost 

 an infinity of objects, and to obtain from the intellect the most solid 

 and permanent enjoyments. 



I shall conclude this subject with the remark that although the 

 attention works only by means of the individual's inner feeling when 

 aroused by a need, usually a moral need, it is nevertheless one of the 

 essential faculties of the intellect, and is only carried on in the organ 

 which produces these faculties. Hence there is justification for the 

 belief that no being which is destitute of this organ could give attention 

 to any object. 



This section on attention might well be extended, for the subject 

 seems to me very important to investigate, and I am firmly convinced 

 that without a knowledge of the necessary condition under which a 

 sensation can produce an idea, we should never have been able to 

 grasp the matters connected with the formation of ideas, thoughts, 

 judgments, etc., nor the cause why most animals which have the same 

 senses as man only form very few ideas, vary them with difficulty, 

 and are dominated by the influence of habit. 



There is therefore good ground for the belief that no operation of 

 the organ of the understanding can take place unless the organ is 

 prepared by attention ; and that our ideas, thoughts, judgments, 

 and reasonings, only continue so long as the organ, in which they are 

 carried on, is maintained in a proper condition for producing them. 



Since the nervous fluid is the chief instrument in an act of attention, 

 a certain quantity of it is consimied when that act is in progress. Now 

 if it lasts too long, the individual becomes so fatigued and exhausted, 

 that the other functions of his organs suffer proportionally. Hence 

 men who think much, and are constantly meditating, and have acquired 

 the habit of straining their attention almost incessantly on things 

 that interest them are much enfeebled in their digestive faculties and 

 muscular power. 



Let us now pass on to an examination of thought, the second of the 

 principal intellectual faculties, though the earliest and most universal 

 of its operations. 



OF THOUGHT. 



The Second of the Principal Faculties of the Intellect. 



Thought is the most universal of intellectual acts, for if we exclude 

 attention, which is the condition of thought, and the other acts of the 

 understanding, thought really embraces all the rest and yet deserves to 

 be especially distinguished. 



