"The Ones Who Walk Away from Omelas" is more of a thought experiment than a conventional short story. It poses a moral question: is our collective happiness and well-being morally acceptable when it is founded on the suffering of another? If I were to condense the core meaning of this short story down to a single sentence, it would be that question.
Ultimately, LeGuin is levying a criticism against utilitarianism, an approach to ethics which understands moral decision-making as a kind of moral mathematics in which the consequences (or expected consequences) of one's actions should determine how one ought to act. Morally optimal decisions are understood as those that would result in maximal happiness (preferably for the greatest number of people) while accruing the lowest cost in suffering.
LeGuin's thought experiment in Omelas ultimately takes this moral theory to its most radical conclusion. What if we can guarantee maximal happiness (and create a utopia) while reducing the cost in...
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