588 THE POPULAR SCIENCE MONTHLY. 



reptiles. Nevertheless, a bat was all the while a mammal, and a ptero- 

 dactyl was not a bird ; and it admits of proof as definite, that what 

 we call instinct in animals occurs in man, and that what we call reason 

 in man occurs in animals. This, I mean, is the case if we wait to 

 attach any definition to the words which we employ. It is quite evi- 

 dent that there is some difference between the mind of a man and the 

 mind of a brute, and if, without waiting to ascertain what this differ- 

 ence is, we say that it consists in the presence or absence of the faculty 

 of reason, we are making the same kind of mistake as when we say 

 that the difference between a bird and a mammal consists in the pres- 

 ence or absence of the faculty of flying. Of course, if we choose, we 

 may employ the word " reason " to signify all the differences taken 

 together, whatever they may be ; and so, if we like, we may use the 

 word " flying." But in either case we should be talking nonsense, be- 

 cause we should be divesting the words of their moaning, or proper 

 sense. The meaning of the word " reason " is the faculty of ratiocina- 

 tion — the faculty of drawing inferences from a perceived equivalency 

 of relations, no matter whether the relations involve the simplest men- 

 tal perceptions, or the most abstruse mathematical calculations. And 

 in this, the only real and proper sense of the word, reason is not the 

 special prerogative of man, but occurs through the zoological scale at 

 least as far down as the articulata. 



What, then, is to be our definition of instinct ? 



First of all, instinct involves mental operation, and therefore im- 

 plies consciousness. This is the point which distinguishes instinct 

 from reflex action. Unless we assume that a new-born infant, for ex- 

 ample, is conscious of sucking, it is as great a misnomer to term its 

 adaptive movements in the performance of this act instinctive as it 

 would be similarly to term the adaptive movements of its stomach 

 subsequently performing the act of digestion. 



Next, instinct implies hereditary knowledge of the objects and re- 

 lations with respect to which it is exercised ; it may therefore operate 

 in full perfection prior to any experience on the part of the individual. 

 When the pupa of a bee, for instance, changes into an imago, it passes 

 suddenly from one set of experiences to another — the difference between 

 its previous life as a larva and its new life as an imago being as great 

 as the difference between the lives of two animals belonging to two 

 different sub-kingdoms ; yet as soon as its wings are dry it exhibits all 

 the complex instincts of the mature insect in full perfection. And the 

 same is true of the instincts of vertebrated animals, as we know from 

 the researches of the late Mr. Douglas Spalding and others. . 



Again, instinct does not imply any necessary knowledge of the rela- 

 tion between means employed and ends attained. Such knowledge 

 may be present in any degree of distinctness, or it may not be present 

 at all ; but in any case it is immaterial to the exercise of the instinct. 

 Take, for example, the instinct of the Bembex, This insect brings 



