441 
and to in e JH elled *!v illC !" de them in tIie sami = category, 
and to invest them with whatever attributes we may have 
deduced from an examination of the general principled n our 
own natures If, for example, I wish to ascertain how far the 
action of a dog who flies at my throat under the influence of 
anger is automatic, I may, by examining the corresponding 
passion m my own nature, plainly discern a feeling which tends 
to produce an action immediately beneficial to myself, in that 
i conduces to the injury and consequent incapacitating of the 
individual from whom 1 have received, or from whom I antici- 
pate the reception of, an injury; and I perceive further that the 
passion is excited and leads to the action independentlv of the 
reason; for my reason, founded on my own knowledge, may 
approve or disapprove of the action according to circumstances ; 
and generally speaking, we may conclude from the phenomena 
of its external manifestation that the passion of anger in the 
dog is as automatic as the same passion in ourselves, and that it 
is excited irrespectively of any conviction in the mind of the 
animal of the benefit accruing from the action which it pro- 
duces. The same analogy may be applied to the other passions 
and appetites which the animal possesses in common with man 
6. And although we cannot employ this analogy, at least so 
ully m determining the nature of those instincts which are 
peculiar to different species of animal, and which are apparently 
wanting m the human psychology, yet we may detect, even in 
these instincts certain features which we have ascertained by 
observation to be generally characteristic of instinct, i.e. by ob- 
serving the phenomena of that principle in ourselves, thus 
the nest-building instinct of birds has no parallel in the human 
psychology ; but we may safely assume that the bird does build 
its nest m obedience to an internal impulse ; because we see 
that it will build the nest even when it cannot know by ex- 
perience, or from information imparted to it by other birds, the 
object for which the nest is intended. And, besides the fact 
of this action being prior to experience, it presents another 
characteristic of instinct, viz., uniformity . A man, who is not 
impelled to build his house by an innate desire, will employ his 
intellect m considering what sort of house is suitable to his 
wants ; and the style of his house will be further determined 
by the means at his disposal,* or his desire to imitate others, 
' ] T , he ^sometimes compelled by circumstances to depart from his 
usual hue of conduct. The beaver, who has been known to construct a dam 
out of the furniture of a drawing-room, modifies his actions somewhat in 
intelligence 6 ° f ^ absenCe ° f trees and water - thU does not prove his 
2k 2 
