122 “The Descent of Man” 
the higher animals may be, it is undoubtedly only a difference “of 
degree and not of kind.” 
In the fourth chapter Darwin deals with the moral sense or 
conscience, which is the most important of all differences between 
man and animals. It is a result of social instincts, which lead to 
sympathy for other members of the same society, to non-egoistic 
actions for the good of others. Darwin shows that social tendencies 
are found among many animals, and that among these love and kin- 
sympathy exist, and he gives examples of animals (especially dogs) 
which may exhibit characters that we should call moral in man 
(e.g. disinterested self-sacrifice for the sake of others). The early 
ape-like progenitors of the human race were undoubtedly social. 
With the increase of intelligence the moral sense develops farther ; 
with the acquisition of speech public opinion arises, and finally, 
moral sense becomes habit. The rest of Darwin’s detailed discussions 
on moral philosophy may be passed over. 
The fifth chapter may be very briefly summarised. In it Darwin 
shows that the intellectual and moral faculties are perfected through 
natural selection. He inquires how it can come about that a tribe at 
a low level of evolution attains to a higher, although the best and 
bravest among them often pay for their fidelity and courage with 
their lives without leaving any descendants. In this case it is the 
sentiment of glory, praise and blame, the admiration of others, 
which bring about the increase of the better members of the tribe. 
Property, fixed dwellings, and the association of families into a 
community are also indispensable requirements for civilisation. In 
the longer second section of the fifth chapter Darwin acts mainly as 
recorder. On the basis of numerous investigations, especially those 
of Greg, Wallace, and Galton, he inquires how far the influence of 
natural selection can be demonstrated in regard to civilised nations. 
In the final section, which deals with the proofs that all civilised 
nations were once barbarians, Darwin again uses the results gained 
by other investigators, such as Lubbock and Tylor. There are two 
sets of facts which prove the proposition in question. In the first 
place, we find traces of a former lower state in the customs and 
beliefs of all civilised nations, and in the second place, there are 
proofs to show that savage races are independently able to raise 
themselves a few steps in the scale of civilisation, and that they have 
thus raised themselves. 
In the sixth chapter of the work, Morphology comes into the 
foreground once more. Darwin first goes back, however, to the 
argument based on the great difference between the mental powers 
of the highest animals and those of man. That this is only quanti- 
1 Descent of Man, p. 193, 
