Why did John Stuart Mill think people should usually follow moral rules instead of calculating consequences every time?

John Stuart Mill argued that individuals should not attempt to calculate the consequences of every single action to determine if it maximizes utility. Instead, he believed that people should be guided by general moral principles—such as those regarding truthfulness, honesty, and justice—because adhering to these established rules generally tends to increase overall happiness.12

Mill’s approach sought to make utilitarianism compatible with conventional moral convictions, avoiding implications that might otherwise seem shocking or impractical. By following these broad principles, individuals can act effectively without the need for constant, complex deliberation. According to Mill, it is only under special circumstances that one might need to consider whether an exception to a general rule is necessary to achieve a better outcome. This perspective provided the foundation for what later became known as rule-consequentialism, an approach designed to align utilitarian goals with the practical realities of human moral decision-making.1234