To prevent the weaker members of the community from being preyed upon by innumerable vultures, it was needful that there should be an animal of prey stronger than the rest, commissioned to keep them down. But as the king of vultures would be no less bent upon preying upon the flock than any of the minor harpies, it was indispensable to be in a perpetual attitude of defense against his beak and claws.

During his time as an MP Mill advocated easing the burdens on Ireland. In 1866 Mill became the first person in the history of Parliament to call for women to be given the right to vote vigorously defending this position in subsequent debate. And as most opinions are neither completely true nor completely false he points out that allowing free expression allows the airing of competing views as a way to preserve partial truth in various opinions.

He was a proponent of utilitarianism an ethical theory developed by Jeremy Bentham. Mill's conception of liberty justified the freedom of the individual in opposition to unlimited state control.