Urantia Book on THE MAINTENANCE OF CIVILIZATION -- HUMAN RESOURCES.

Man poweer is indespensable to the spread of civilization. All things equal, a numerous people will dominate the civilization of a smaller race. Hence failure to increase in numbers up to a certain point prevents the full realization of national destiny, but there comes a point in population increase where further growth is suicidal. multiplication of numbers beyond the optimum of the normal man-land ratio means either a lowering of the standards of living or and immediate expansion of territorial boundaries by peaceful penetration or by military conquest, forcible occupation.

The Optimum stabilization of the national population enhances culture and prevents war. And it is a wise nation which knows when to cease growing.