INSTINCT. 



tions, the sensations, the voluntary powers, the 

 memory and instinct of the animals are all 

 brought into play ; but we have no reason to 

 believe that the animals performing them are 

 capable of anticipating their ultimate result. 



In all cases, those actions which are en- 

 titled to the appellation of Instinctive are ge- 

 nerally xmderstood to be characterized by two 

 marks, quite sufficient to distinguish them from 

 the effects of voluntary power guided by rea- 

 son : 1. That, although in many cases expe- 

 rience is required to give the will command 

 over the muscles concerned in them, yet the 

 will, when under the influence of the instinc- 

 tive determination, acts equally well the first 

 time as the last ; no experience or education is 

 required, in order that the different voluntary 

 efforts requisite for these actions may follow 

 one another with unerring precision; and 2. 

 That they are always performed by the same 

 species of animal nearly, if not exactly, in the 

 same manner ; presenting no such variation of 

 the means applied to the object in view, and 

 admitting of no such improvements in the pro- 

 gress of life or in the succession of ages, as 

 we observe in the habits of individual men, or 

 in the manners and customs of nations, adapted 

 to the attainment of any particular ends by 

 those voluntary efforts which are guided by 

 Reason. " The manufactures of animals," says 

 Dr. Reid, " differ from those of men in many 

 striking particulars. No animal of the species 

 can claim the invention. No animal ever in- 

 troduced any new improvement, or variation 

 from the former practice. Every one has equal 

 skill from the beginning, without teaching, 

 without experience or habits. Every one has 

 its art by a kind of inspiration, i. e. the ability 

 and inclination of working in it without any 

 knowledge of its principles." A third distinc- 

 tive mark, naturally resulting from the last, 

 is at least equally characteristic, although much 

 less generally observable, that these instinc- 

 tive actions are seen to be performed in cir- 

 cumstances which reason informs us to be such 

 as to render them nugatory for the ends which 

 are usually accomplished by them, and for 

 which they are obviously designed. The 

 efforts made by migratory birds, even when 

 confined, at their usual period of migration, 

 the mistake of the flesh-fly who deposits her 

 eggs on the carrion-plant instead of a piece of 

 meat,* or of the hen who sits on a pebble in- 

 stead of an egg, or of the mule which remains 

 immoveably fixed by terror instead of escaping 

 from the flood which threatens to overwhelm it, 

 (as exemplified in the inundation of the valley 

 of Luisnes in Savoy in 1818,) or of the bee 

 which gathers and stores up honey even in 

 a climate where there is no winter, f are so 

 many proofs, that an instinctive action is 

 prompted by an impulse, which results merely 

 from a particular sensation or emotion being 

 felt, not by anticipation of the effect which the 

 action will produce. 



* Kiiby. 



t See Kirby and Spcncr, Introduction to Ento- 

 mology, vol. ii. p. 469. 



But, in order to have demonstrative proof 

 of the essential difference between instinct and 

 reason, and of the correctness of the view 

 which we take of the nature of that mental 

 impulse which prompts what we call the in- 

 stinctive actions of animals, it is only neces- 

 sary to reflect on what passes within ourselves 

 on occasion of certain actions of the very 

 same class being performed by us. It is dif- 

 ficult, indeed, in adult age, to distinguish 

 those actions which we perform instinctively 

 from those which we have learnt by repeated 

 efforts to perform habitually ; but in the case 

 of infants we see complex actions, useful or 

 necessary to the system, performed -with per- 

 fect precision at a time when we are certain 

 that the human intellect is quite incompetent 

 to comprehend their importance or anticipate 

 their effects ; yet we cannot doubt that it is by 

 a mental impulse that they are excited, because 

 we perform the same actions in the same cir- 

 cumstances in adult age, and are then con- 

 scious of the impulse which prompts them. 

 " It is an instinct," says Bichat, " which I do 

 not understand, and of which I cannot give 

 the smallest account, which makes the infant, 

 at the moment of birth, draw together its lips 

 to commence the action of sucking," to be fol- 

 lowed by the still more complex act of deglu- 

 tition. " This cannot be ascribed to the mere 

 novelty of the sensations which it experiences 

 from external objects, for the general effect of 

 such sensations is to determine various agita- 

 tions or irregular movements indeed, but not 

 an uniform movement, directed to a deter- 

 minate end. If we examine different animals 

 at the moment of birth, we shall see that the 

 special instinct of each directs the execution 

 of peculiar movements. Young quadrupeds 

 seek the mammae of their mothers, birds of 

 the order Gallinacese seize immediately the 

 grain which is their appropriate nourishment, 

 while the young of the Carnivorous birds 

 merely open their mouths to receive the food 

 which their parents bring to their nests. In 

 general, it is very important to distinguish the 

 irregular or varied movements which, at the 

 moment of birth, are produced simply by the 

 new sensations and excitements which the body 

 receives, from those definite actions which are 

 the effect of instinct, a cause of which we can 

 give no further explanation." 



In fact, when we attend to the simple action 

 of deglutition,* as performed in our mature 

 years, we may be conscious that it results from 

 the same instinctive impulse which guided it 

 with unerring precision in the new-born infant, 

 long before the voluntary power of simply 

 raising the hand to the mouth had been ac- 

 quired. If we were to consult only the grati- 

 fication of our sensations, we should keep any 

 grateful food in the mouth ; for when it is swal- 

 lowed the gratification immediately resulting 

 from it is at an end, and there is no peculiar 

 pleasure attached, in other circumstances, to 

 the mere act of deglutition; but all we can 



* [I. e. that part of the act which is dependent 

 on the voluntary movement of the tongue to pass 

 on the food to the isthmus faucium. ED.] 



