650 SCIENCE PROGRESS 



of hurt to persons whom they cherish, even at the idea of injury to, or depre- 

 ciation of, these persons. On the other side, too, we find that the impulse 

 to act may take outlet in equally various directions. To some extent the 

 nature of the action will depend on the intensity of the emotion ; so that a 

 man who on one occasion would immediately strike his antagonist, would 

 on another occasion defer his retaliation until he could make it more effec- 

 tive. Or, in another way, a man might make it a practice to check his 

 impulse to strike, because he held certain ideas about the effect of physical 

 force. We can now see that two parts of the experience are quite definitely 

 capable of variation, and also that the impulse given by the emotion may be 

 greatly controlled. It only remains to add that the central part of the 

 experience, the actual emotional disturbance, appears to be unchangeable 

 for each individual. This capacity is one part of his inheritance which is 

 not subject to modification as a result of experience. 



We can now say that an instinct is an inherited or innate tendency to 

 experience a definite emotion when we become aware of certain things, and 

 also to experience an impulse to act in a similarly definite manner. 



We have merely to consider the principal instincts for a moment in order 

 to realise the determining effect they have on life as a whole. The parental 

 instinct, with its corresponding emotion, known as the tender emotion, has 

 effects which reach far along the line of social life. And if we take with 

 it the reproductive instinct, we get a combination that plays perhaps a 

 greater part in life than any other instinct. In some animals, these two 

 instincts do not always act together ; it is found that in the males of some 

 species the parental instinct is not shown. But in the case of females, it 

 is almost invariably strong ; and it is needless to point out the value of 

 this in protecting and rearing the young during their period of dependence. 

 In human beings, however, it is only in depraved natures that these two 

 instincts do not operate together. As regards the vast majority, we can 

 easily see the far-reaching influence in the fact that our social life has as its 

 base the family. There is no need here to record instances of the extent to 

 which men and women sacrifice themselves for their children at the prompting 

 of the parental instinct. While in the case of the father the instinct may 

 not appear to be very strong, that is largely because of the degree to which 

 woman effaces her own desires and needs for the sake of her children. The 

 working of the instinct, also, is not confined to immediate needs ; it prompts 

 the parents to look far into the future and make plans for the well-being of 

 the offspring years ahead. It is the cause of an amount of suffering and 

 self-sacrifice which is not paralleled in any other relation in life. 



While we are dealing with the parental instinct, it is worth while to 

 remark that it is very probably from its emotion that altruistic conduct 

 in any form arose. As society emerged from its simple form, where the 

 tribe was the largest unit, the tender emotion man experienced towards his 

 family or tribe made it possible for him to develop a similar — though no 

 doubt less intense — feeling for his fellows ; and as a result rendered the 

 extension of the range of his society more easy. It is very likely, also, that 

 from this same source there sprung the idea of the whole human race as 

 one family. 



In connection with the position of man in family, tribe, and nation, 

 there is another instinct that works in a binding way, and that is the gre- 

 garious or herd instinct. The animals other than man, of course, present 

 very many instances of this instinct in its simplest form. When an animal 

 has become detached from the herd, it is not always fear that makes it run 

 at once to its fellows. The same tendency occurs when the possibility of 

 fear is ruled out. And we see animals in some cases perform actions which 

 can only be interpreted as expressive of satisfaction at being again in the 

 herd : as, for example, when a cow rejoins the herd and rubs itself against 



