146 MENTAL CHARACTERISTICS OF MAN. 



is about the same, so far as can be ascertained. The age to 

 which the life of Man is ordinarily prolonged under favourable 

 circumstances, may be stated as about seventy-five years , but 

 it frequently surpasses a hundred, and this among individuals 

 of all nations. 



136. It cannot be doubted, however, that the mental endow- 

 ments of Man, and the habits of life which result from them, 

 distinguish him much more completely from the lower animals, 

 than do the peculiarities of his bodily structure and actions. In 

 the highest among brutes, the mere instinctive propensities are the 

 frequent springs of action (ANIM. PHYSIOL. Chap, xiv.) ; and 

 though the intelligence and will may operate to a certain extent, 

 the character never rises beyond that of the child. In fact, the 

 correspondence between the mental faculties of the Chimpanzee, 

 and those of the Human infant of between two and three years old, 

 is very close. In adult Man, however, the instinctive propen- 

 sities only manifest themselves strongly, when the intellect is 

 undeveloped ; and nearly all his actions are performed tinder the 

 immediate guidance of his intelligent will. From the intelligence 

 of Man results his power of improvement ; and this, acting from 

 generation to generation, is the cause of the comforts now enjoyed 

 by civilized races, and of the means which they possess of still 

 further civilization. In the mode in which these are attained, 

 we observe a remarkable difference between the character of 

 Man, and that of the lower animals. The arts of which they 

 are capable, are limited and peculiar to each species ; and there 

 seems to be no general power of adapting these to any great 

 variety of purposes, or of profiting by the experience of others. 

 Where a particular adaptation of means to ends, of actions to 

 circumstances, is made by an individual (as is frequently the case 

 where some amount of intelligence or rationality exists), the 

 rest do not seem to profit by it (ANIM. PHYSIOL. 695) ; so that 

 there is no proof of any species or race, among the lower animals, 

 ever making an advance towards an improvement or alteration 

 in its condition. It has been already pointed out ( 110), that 

 modifications in structure and instincts may be induced by cir- 

 cumstances in some of the most improvable species ; but, in 



