 What is the meaning of Dondromogon’s two extreme hemispheres?
It is as well, for this will be a birth and beginning of your destined leadership on Dondromogon." The voice was telling me that I had been snatched from worlds away, for a specified purpose here on whatever windswept planet Dondromogon might be. One face of Dondromogon ever looks to the light and heat, wherefore its metals run in glowing seas. But because Dondromogon wavers on its axis, there are two lunes of its surface which from time to time shift from night to day. My eyes were tight shut against the dust, but they saw in imagination such a planet—one-half incandescent, one-half pitchy black. From pole to pole on opposite sides ran the two twilight zones, widest at the equators like the outer rind of two slices of melon. Of course, such areas, between the hot and cold hemispheres, would be buffeted by mighty gales ... the voice was to be heard again: "War is fought between the two strips of habitable ground. Dondromogon was found and settled long ago, by adventurers from afar. There is a proper time, like a proper place, for each thing and each happening. On this strange world called Dondromogon, what manner of intelligent life bade defiance to heat and cold and storm, and built these stout structures, and now laid hands—were they hands indeed?—upon me? Especially as I don't know who I am, or where I'm from, or anything that has happened longer ago than just a moment.
 It causes its inhabitant groups to fight over what amount of the planet is habitable, the two extremes symbolizing the split between peoples.
 It causes its people to develop two vastly different cultures, creating social tension.  It causes its people to search for prophets, martyrs, and heroes, symbolizing the schizophrenia of the planet’s inhabitants.  It causes its people to live underground, giving the story its setting.  It causes its inhabitant groups to fight over what amount of the planet is habitable, the two extremes symbolizing the split between peoples.