Intellectual and Moral Faculties 121 
implements will be read with interest; these are similar to the 
observations on modern eoliths, and their bearing on the develop- 
ment of the stone-industry. It is interesting to learn from a letter 
to Hooker}, that Darwin himself at first doubted whether the stone 
implements discovered by Boucher de Perthes were really of the 
nature of tools. With the relentless candour as to himself which 
characterised him, he writes four years later in a letter to Lyell in 
regard to this view of Boucher de Perthes’ discoveries: “I know 
something about his errors, and looked at his book many years ago, 
and am ashamed to think that I concluded the whole was rubbish ! 
Yet he has done for man something like what Agassiz did for 
glaciers®.” 
To return to Darwin’s further comparisons between the higher 
mental powers of man and animals. He takes much of the force 
from the argument that man alone is capable of abstraction and 
self-consciousness by his own observations on dogs. One of the 
main differences between man and animals, speech, receives detailed 
treatment. He points out that various animals (birds, monkeys, 
dogs) have a large number of different sounds for different emotions, 
that, further, man produces in common with animals a whole series 
of inarticulate cries combined with gestures, and that dogs learn to 
understand whole sentences of human speech. In regard to human 
language, Darwin expresses a view contrary to that held by Max 
Miiller?: “I cannot doubt that language owes its origin to the 
imitation and modification of various natural sounds, the voices of 
other animals, and man’s own instinctive cries, aided by signs and 
gestures.” The development of actual language presupposes a 
higher degree of intelligence than is found in any kind of ape. 
Darwin remarks on this point‘: “The fact of the higher apes not 
using their vocal organs for speech no doubt depends on their 
intelligence not having been sufficiently advanced.” 
The sense of beauty, too, has been alleged to be peculiar to man. 
In refutation of this assertion Darwin points to the decorative colours 
of birds, which are used for display. And to the last objection, that 
man alone has religion, that he alone has a belief in God, it is 
answered “that numerous races have existed, and still exist, who 
have no idea of one or more gods, and who have no words in their 
languages to express such an idea',” 
The result of the investigations recorded in this chapter is to 
show that, great as the difference in mental powers between man and 
1 Life and Letters, Vol. 1. p. 161, June 22, 1859. 
2 Ibid. Vol. 11. p. 15, March 17, 1863. 
3 Descent of Man, p. 132. 4 Ibid. pp. 136, 137. 
5 Ibid. p. 143. 
