This is discussing a critique of pure utilitarian decision-making and majority-rule democracy. Let me break down the key points:

The core argument is about situations where an action would:
-Severely harm a small group of people
-Provide small benefits to a large group of people

Even if the total utility (multiplying number of people × benefit/harm) suggests the action is "good," the author argues this calculation breaks down when the harm to individuals becomes very severe.

The author sees this as particularly problematic in democratic voting because:
-The larger group can always outvote the smaller group
-Most people vote in their self-interest, even for tiny personal gains
-This can lead to severely harmful outcomes for minorities

They note that sometimes people do vote against their immediate self-interest due to:
-Misunderstanding the situation
-Being misled by experts
-Having enough resources to be generous
-Moral considerations

The conclusion questions whether "one person, one vote" is truly fair when comparing:
-One voter who slightly prefers an option
-Another voter who would be devastated by that same option

It's essentially arguing for some form of weighted consideration where severe negative impacts should carry more weight than minor positive ones, even if they affect fewer people - a critique of both pure utilitarianism and simple majority rule.