What Are the main Themes in the short story "Once Upon A Time" By Nadine Gordimer

I sense that there are two dominant themes that arise from Gordimer's work.  The first would be the fear of "the other."  The family's drive to protect themselves and essentially shield themselves from the outside world represents an inherent fear of that which is unknown.  This fear is the driving force behind inwardly drawn communities and also represents a large and underlying rationale of apartheid in Gordimer's own native South Africa.  The attitudes of the family help to develop this theme of a fear of that which is unknown or misunderstood.  The tragic condition of the family at the end, resulting the death of their child, is a result of this fear.  Another theme in the work is the idea of the dualistic and reciprocal nature of creation and destruction.  This holds the idea that each act of creation is an inevitable step towards destruction.  The family seeks to create a "perfect" solution to their fear of the outside world.  In barricading themselves off, they feel they have "the answer."  However, with each advancing step in this vein, they actually move a step closer to destruction and terror, as they move farther away from rationality and understanding and closer to a domain where destruction is the only logical end.