SEXUAL SELECTION IN RELATION TO MAN 785 



to invent and use language, to make weapons, t&ols, traps, 

 etc., whereby, with the aid of his social habits, he long 

 ago became the most dominant of all living creatures. 



A great stride in the development of the intellect will 

 have followed, as soon as the half art and half instinct of 

 language came into use; for the continued use of language 

 will have reacted on the brain and produced an inherited 

 effect; and this again will have reacted on the improve- 

 ment of language. As Mr. Ohauncey Wright' h.as well 

 remarked, the largeness of tlie brain in man, relatively to 

 his body, compared with the lower animals, may be attrib- 

 uted in chief part to the early use of some simple form of 

 language — that wonderful engine which affixes signs to all 

 sorts of -objects and qualities, and excites trains of thought 

 which would never arise from the mere impression of the 

 senses, or if they did arise could not be followed out. The 

 higher intellectual powers of man, such as those of ratioci- 

 nation, abstraction, self -consciousness, etc., probably follow 

 from the continued improvement and exercise of the other 

 mental faculties. 



The development of the moral qualities is a more inter- 

 esting problem. The foundation lies in the social instincts, 

 including under this term the family ties. These instincts 

 are highly complex, and in the case of the lower animals 

 give special tendencies toward certain definite actions; but 

 the more important elements are love, and the distinct emo- 

 tion of sympathy. Animals endowed with the social in- 

 stincts take pleasure in one another's company, warn one 

 another of danger, defend and aid one another in many 

 ways. These instincts do not extend to all the individ- 

 uals of the species, but only to those of the same commu- 

 nity. As they are highly beneficial to the species, they 

 have in all probability been acquired through natural 

 selection. 



A moral being is one who is capable of reflecting on 



• "Qn the Limits of Natural Selection," in the "North American Review," 

 Oct. 1870, p. 299. 



