From time to time all of these different peoples experienced cultural and spiritual revivals. Mansant was a great teacher of the post-Planetary Prince days. But mention is made only of those outstanding leaders and teachers who markedly influenced and inspired a whole race. With the passing of time, many lesser teachers arose in different regions; and in the aggregate they contributed much to the sum total of those saving influences which prevented the total collapse of cultural civilization, especially during the long and dark ages between the Caligastia rebellion and the arrival of Adam.

There are many good and sufficient reasons for the plan of evolving either three or six colored races on the worlds of space. Though Urantia mortals may not be in a position fully to appreciate all of these reasons, we would call attention to the following:

1. Variety is indispensable to opportunity for the wide functioning of natural selection, differential survival of superior strains.

2. Stronger and better races are to be had from the interbreeding of diverse peoples when these different races are carriers of superior inheritance factors. And the Urantia races would have benefited by such an early amalgamation provided such a conjoint people could have been subsequently effectively upstepped by a thoroughgoing admixture with the superior Adamic stock. The attempt to execute such an experiment on Urantia under present racial conditions would be highly disastrous.

3. Competition is healthfully stimulated by diversification of races.

4. Differences in status of the races and of groups within each race are essential to the development of human tolerance and altruism.

5. Homogeneity of the human race is not desirable until the peoples of an evolving world attain comparatively high levels of spiritual development.

When the colored descendants of the Sangik family began to multiply, and as they sought opportunity for expansion into adjacent territory, the fifth glacier, the third of geologic count, was well advanced on its southern drift over Europe and Asia. These early colored races were extraordinarily tested by the rigors and hardships of the glacial age of their origin. This glacier was so extensive in Asia that for thousands of years migration to eastern Asia was cut off. And not until the later retreat of the Mediterranean Sea, consequent upon the elevation of Arabia, was it possible for them to reach Africa.

Thus it was that for almost one hundred thousand years these Sangik peoples spread out around the foothills and mingled together more or less, notwithstanding the peculiar but natural antipathy which early manifested itself between the different races.

Between the times of the Planetary Prince and Adam, India became the home of the most cosmopolitan population ever to be found on the face of the earth. But it was unfortunate that this mixture came to contain so much of the green, orange, and indigo races. These secondary Sangik peoples found existence more easy and agreeable in the southlands, and many of them subsequently migrated to Africa. The primary Sangik peoples, the superior races,