21 6 PHILOSOPHY OF ZOOLOGY. 



ed in all the various circumstances in which they present 

 themselves. This power or effort of the mind is termed 



1. Attention. Unless this power is exercised on the or- 

 gans of perception, the impressions which are produced 

 are confused and obscure, and speedily vanish. But, by its 

 means, the organs are brought into a condition suitable to 

 receive an impression and determine its nature and dura- 

 tion, and preserved therein a sufficient length of time. 



In the exercise of Attention, we seldom are capable of . 

 employing more than one sense at a time ; but can, without 

 much difficulty, fix the mind on several different kinds of 

 information which one sense is capable of communicating. 

 Thus, we can distinguish a variety of conditions in sound, 

 and the impressions produced on the organs of sight. 

 But this faculty chiefly displays its peculiar nature and its 

 utility, in its selective operations. Thus, for example, in 

 looking at a rose, I can either attend to its size, its subdivi- 

 sions, colour or fragrance. The character on which I am 

 said to bestow the greatest attention, is the one to which I 

 direct the suitable organ of sensation with the greatest in- 

 tensity, for the greatest length of time, and of which I am 

 said to have the most distinct conception. Man employs 

 this essential faculty of his mind, in every inquiry he makes, 

 and in almost every action which he performs. Without 

 its assistance and controul, no knowledge of external ob- 

 jects can be gained, no train of reflection can be pursued, 

 no successful bodily effort can be made. 



In the lower animals, this faculty not only exists, but dis- 

 plays itself to our observation in various ways. What is it but 

 the exercise of attention, when we see a cat watching for a 

 mouse, or a kestril hovering in the air ? In both cases, the 

 faculty now under consideration is exercising its controul 

 over the organs of sight. When we witness the fox-hound 

 engaged in the chace, we see attention regulating the or- 



