90 
THE DESCENT OF MAN. 
Part I- 
of such feelings would be an unnatural monster. On 
the other hand, the desire to satisfy hunger, or any 
passion, such as vengeance, is in its nature temporary, 
and can for a time be fully satisfied. Nor is it easy, 
perhaps hardly possible, to call up with complete vivid- 
ness the feeling, for instance, of hunger ; nor indeed, as 
has often been remarked, of any suffering. The in- 
stinct of self-preservation is not felt except in the pre- 
sence of danger ; and many a coward has thought him- 
self brave until he has met his enemy face to face. 
The wish for another man’s property is perhaps as 
persistent a desire as any that can be named ; but even 
in this case the satisfaction of actual possession is gene- 
rally a weaker feeling than the desire : many a thief, if 
not an habitual one, after success has wondered why be 
stole some article. 
Thus, as man cannot prevent old impressions con- 
tinually repassing through his mind, he will be com- 
pelled to compare the weaker impressions of, for in- 
stance, past hunger, or of vengeance satisfied or danger' 
avoided at the cost of other men, with the instinct of 
sympathy and good-will to his fellows, which is still pre- 
sent and ever in some degree active in his mind. He 
will then feel in his imagination that a stronger instinct 
has yielded to one which now seems comparatively 
weak ; and then that sense of dissatisfaction will in- 
evitably be felt with which man is endowed, like every 
other animal, in order that his instincts may be obeyed- 
The case before given, of the swallow, affords an illus- 
tration, though of a reversed nature, of a temporary 
though for the time strongly persistent instinct con- 
quering another instinct which is usually dominant over 
all others. At the proper season these birds seem all 
day long to be impressed with the desire to migrate ; 
their habits change ; they become restless, are noisy- 
