People listened when Mill spoke about a vital issue. Mill’s opinion had to be reckoned with because he was the most influential English philosopher of the nineteenth century, the author of respected books on economics, logic, and political philosophy, a prolific journalist, the editor of a widely followed journal of opinion, a friend of leading intellectuals in Europe and the United States. He didn’t anticipate how socialist government power could unleash horrifying intolerance during the twentieth century. As far as Mill was concerned, Utilitarianism became a moral plea for socialism. Neither Mill nor any other Utilitarian offered fixed principles to replace natural rights. Natural rights, as explained by thinkers like Thomas Jefferson and Thomas Paine, defined what governments could not rightfully do. Mill and other Utilitarians relentlessly attacked the doctrine of natural rights, a moral basis for liberty which had provided the only known intellectual barrier to tyranny. Yet from the standpoint of liberty generally, the philosophy behind On Liberty–Utilitarianism–was a terrible failure.

The book inspired generations of classical liberal thinkers, and today it is probably the only historic work about toleration that most people ever read. It defends toleration-of thought, speech, and individuality-as a practical means to promote happiness for the greatest number of people. It is clear, concise, logical, and passionate. John Stuart Mill’s essay On Liberty (1859) is the most famous work about toleration in the English language.

Js mill on liberty