THE NATURE AND SCOPE
towards all the others, and the vindication of this attitude in ourselves requires that we, for the sake of all, should endeavor to determine, not the reason for our own superiority, but how man everywhere has come to be as he is.
2. The problem so stated is not new, and many theories have been advanced to account for the manifest differences in human groups. Of these theories, the most popular and persistent is that which attributes the diversities among peoples to physical differences in race. Thus it is widely believed that difference of race implies a real and deep-rooted distinction in physical, mental, and moral qualities, and that the contrasts in the achievements of the various peoples are due to differences in physical characteristics. Hence it is thought that one race becomes a master because of its physique, courage, brain-power, and morale, while another sinks in the struggle or lags behind owing to its inferiority in these qualities. This view naturally implies that the same race preserves its character, not only in every region of the world, but in every period of history, and so the course of history would appear as a sustained process of selection between the races that are sluggish, cowardly, and retrogressive, and
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