132 Mr. George J. Romanes [Feb. 8, 



As there are not many words within the compass of our language 

 which have had their meanings less definitely fixed than the word 

 " instinct," it is necessary that I should begin by clearly defining the 

 sense in which I shall use it. 



In general literature and conversation we usually find that instinct 

 is antithetically opposed to reason, and this in such wise that while 

 the mental operations of the lower animals are termed instinctive, those 

 of man are termed rational. This rough and ready attempt at psycho- 

 logical classification has descended to us from remote antiquity, and 

 like kindred attempts at zoological classification, is not a bad one so 

 far as it goes. To divide the animal kingdom into beasts, fowls, fish, 

 and creeping things, is a truly scientific classification as far as it goes, 

 only it does not go far enough for the requirements of more careful 

 observation ; that is to say, it only recognises the more obvious and 

 sometimes only superficial differences, while it neglects the more 

 hidden and usually more important resemblances. And to classify 

 all the mental phenomena of animal life under the term " instinct," 

 while reserving the term " reason " to designate a mental peculiarity 

 distinctive of man, is to follow a similarly archaic method. It is 

 quite true that instinct preponderates in animals, while reason pre- 

 ponderates in man. This obvious fact is what the world has always 

 seen, just as it saw that flying appeared to be distinctive of birds, 

 and creeping of reptiles. Nevertheless, a bat was all the while a 

 mammal, and a pterodactyl 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 evident 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 difference 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 presence 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, because we should be divesting the words of 

 their meaning, or proper sense. The meaning of the word " reason " 

 is the faculty of ratiocination — the faculty of drawing inferences 

 from a perceived equivalency of relations, no matter whether the 

 relations involve the simplest mental 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 

 implies consciousness. This is the point which distinguishes instinct 



