Although his book On Liberty
was indeed highly influential in forming the modern understanding of classical Whig liberalism, Mill frequently supported policies antithetical to it, because he believed in utilitarianism over natural rights. The following famous words from On Liberty-
“… the only purpose for which power can be rightfully exercised over any member of a civilized community against his will is to prevent harm to others. His own good, either physical or moral, is not a sufficient warrant. He cannot rightfully be compelled to do or to forbear because it will be better for him to do so, because it will make him happier, because in the opinions of others to do so would be wise or even right. These are good reasons for remonstrating with him, or reasoning with him, or persuading him, or entreating him, but not for compelling him, or visiting him with any evil in case he do otherwise.”
-are all too easily cast aside by the ultilitarian thought in the sentence that immediately followed:
“To justify that, the conduct from which it is desired to deter him must be calculated to produce evil to someone else.” (On Liberty, ch. 1.)
This is a loophole through which one can drive an entire army. One could surely “calculate” that a free Iraq would “produce evil to someone else,” and hence we may be justified in compelling it to become a modern, liberal, democratic state. But even if we set aside the fact that it is manifestly impossible to accomplish this task, it is clearly a contradiction of the first four sentences of Mill’s statement. Mill’s willingness to set such limits on liberty is, in fact, precisely what begins the movement away from classical liberalism to the odious modern kind.