ON INSTINCT. 277 



whose wants and consequent actions are nearly the same ; and when one 

 animal appears to have more extensive principles of this kind than 

 another, it is because it has a greater scope of action, and of course 

 attended with more variety. 



I shall not instance any of the more imperfect animals [in illustra- 

 tion of instinct], but take the bird and the quadruped. I can conceive 

 that a parrot and a crow have a greater extent of instinctive principles, 

 leading to a greater variety and more neatness in their operations, than 

 a cuckoo or a partridge has. I conceive that monkeys have more 

 extensive instinctive principles than dogs, and dogs more extensive 

 than sheep. And if man could lay aside acting from reasoning, hip 

 instinctive principles would be more extensive than any : but the actions 

 arising from instinct are so heightened and made so much more perfect, 

 that the instinctive actions appear, even to the mind of the persons 

 themselves, to be wholly the result of reason. In crows, where the 

 instinctive principle is pretty well marked, their actions come near to 

 those of the human, [there] being no difference in the action excepting 

 the human varying it a little more according to circumstances. 



Thus a rook builds its nest according to the instinctive principle of 

 the animal, and for this purpose breaks off branches of the trees on 

 or near which it builds : it also gathers sticks on the ground near 

 the nest : but the curious thing is their stealing from one another. Thus 

 a neighbouring rook shall steal the sticks of another : they shall observe 

 the motions of each other, and, when opportunity serves, they imme- 

 diately become thieves. 



It is curious to see how instinctive principles arise. "When we see 

 only the effect, and not the immediate cause, it appears wonderful ; but, 

 when we can trace them, they do not so much surprise us. The im- 

 mediate cause of the bees' instinctive principles is not all laid open to 

 us. It is curious to see the young duck run into the water the moment 

 it sees it. 



When two .instinctive principles oppose one another in two different 

 animals, it is curious to see the conflict. A hen, for instance, with duck- 

 chickens, seeing them run into the water, is unhappy ; and a duck with 

 young hen- chickens, invites her brood into that element, while the 

 chickens are running round the side of the water. 



Instinct is in most respects similar to general principles in arts and 

 sciences ; for neither instinct nor general principles will apply equally 

 to all cases, with which they have an immediate connexion. Instinctive 

 principles are not fitted for, nor take notice of, contingencies ; nor do 

 general principles. A bird, when it builds its nest in a tree, does not 

 consider accidents ; and therefore does not guard against them. A 



