8 Chapter L 



the very name suggests, instinctive actions are those 

 which spring from impulses of the sensitive appetite 

 and are accompanied by sense perceptions and sensile 

 feelings. These two qualities distinguish them from 

 reflex motions. Lastly, they are unconsciously adaptive, 

 and thereby totally different from acts of the intellect. 



Everyone will allow, that instinctive actions are 

 neither mere reflex phenomena nor intellectual functions. 

 They are not mere reflex phenomena, for they contain, 

 as experience teaches, a psychic element which cannot 

 be eliminated without destroying their very essence. 

 Reflex actions are those adaptive processes of a living 

 organism, which solely, but essentially depend on the 

 irritation of certain motory nerves. They are specified 

 by it alone, whether this activity of the motory nerves be 

 connected with an irritation of the sensory nerves or not. 

 Indeed, this latter connection is quite unessential to 

 reflex activity. Consequently sensation is not an es- 

 sential element of reflex acts. Thus the regular pump- 

 ing motions of the heart, which we call palpitations, and 

 the peristaltic motions of the bowels during digestion are 

 reflex actions; but they are not necessarily perceptible. 

 Similarly reflex is the act of sneezing, which is caused 

 by the irritation of certain sensory nerves of the organs 

 of breathing, or the twitchings of certain motory 

 muscles, which are produced by irritations of the spinal 

 ganglia. Therefore reflex actions are due solely to an 

 influence of the nerve mechanism, and the psychic 

 element of sensation is not essential to them. But this 

 is not the case in any process that is truly instinctive. 

 For in all such actions sensation participates as a cause 

 in producing the corresponding activity. Therefore we 



