"Kirinyaga," which is part of a cycle of interrelated short stories,* tells the tale of Koriba, the mundumugu or witch doctor of Kirinyaga, an orbital space-colony that has been made in the image of ancient Kenya as part of a Utopian experiment. The story centres thematically around the idea of the need an adhere to rituals to maintain a culture and, in turn, a cultural identify.
Specifically, it focuses on the ancient Kirinyagan custom of killing a baby that was born feet first, as the belief is that such a child would actually be possessed by a demon. To a modern European or North American, this would seem horrible, a sentiment which is personified in by Maintenance, an all-white group of people who, well, maintain Kirinyaga's space station. However, Koriba argues throughout the story that the Kirinyagans cannot defer to maintenance's requests to abandon this ritual. He argues that, as a part of the rituals of Kirinyagan culture, it is necessary in order to maintain their identities as Kirinyagans, and that the removal of just one piece of the culture, just one ritual, will cause them to cease to be Kirinyagan. It's a surprisingly convincing argument actually, despite the disturbing repercussions of culturally-supported infanticide.
*I should note that, despite being part of a cycle, this story does stand quite well on it's own.