There is certainly great difference in the mental ability of individuals, and there are probably less marked differences in the average ability of different races; but difference in natural ability is, in the main, a characteristic of the individual, not of race or of sex. It is probable that brain efficiency (speaking from the biological standpoint) has been, on the average, approximately the same in all races and in both sexes since nature first made up a good working-model, and that differences in intellectual expression are mainly social rather than biological, dependent on the fact that different stages of culture present different experiences to the mind, and adventitious circumstances direct the attention to different fields of interest. II In approaching the question of the parity or disparity of the mental ability of the white and the lower races, we bring to it a fixed and instinctive prejudice. No race views another race with that generosity with which it views itself. It may even be said that the existence of a social group depends on its taking an exaggerated view of its own importance; and in a state of nature, at least, the same is true of the individual. If self-preservation is the first law of nature, there must be on the mental side an acute consciousness of self, and a habit of regarding the self as of more importance than the world at large. The value of this standpoint lies in the fact that, while a wholesome fear of the enemy is important, a wholesome contempt is even more so. Praising one's self and dispraising an antagonist creates a confidence and a mental superiority in the way of confidence. The vituperative recriminations of modern prize-fighters, the boastings of the Homeric heroes, and the _bôgan_ of the old Germans, like the back-talk of the small boy, were calculated to screw the courage up; and the Indians of America usually gave a dance before going on the war-path, in which by pantomime and boasting they magnified themselves and their past, and so stimulated their self-esteem that they felt invincible. In race-prejudice we see the same tendency to exalt the self and the group at the expense of outsiders. The alien group is belittled by attaching contempt to its peculiarities and habits--its color, speech, dress, and all the signs of its personality. This is not a laudable attitude, but it has been valuable to the group, because a bitter and contemptuous feeling is an aid to good fighting.