In Musk’s dark view of the world, civilization is under threat because of a declining population. He is driven to correct the historic moment by helping seed the earth with more human beings of high intelligence, according to people familiar with the matter.
His businesses are set up to serve the idea: The main objective of SpaceX is to build a rocket ship capable of getting to Mars, and his other companies, including electric-car maker Tesla, help finance the plan.
Musk refers to his offspring as a “legion,” a reference to the ancient military units that could contain thousands of soldiers and were key to extending the reach of the Roman Empire.
https://www.wsj.com/politics/elon-musk-children-mothers-ashley-st-clair-grimes-dc7ba05c