I’ve never been a fan of John Stuart Mill.  Yes, he had a massive IQ and a dreadful Tiger Dad.  But his thinking is shockingly muddled. 

One especially cringeworthy example: In the span of two pages in On Liberty, Mill names one “ultimate” principle and one “absolute” principle.  His Ultimate Principle:

It is proper to state that I forego any advantage which could be derived
to my argument from the idea of abstract right, as a thing independent
of utility. I regard utility as the ultimate appeal on all ethical

His Absolute Principle:

The object of this Essay is to assert one very simple principle, as
entitled to govern absolutely the dealings of society with the
individual in the way of compulsion and control, whether the means used
be physical force in the form of legal penalties, or the moral coercion
of public opinion.

You might think that Mill would argue that his Ultimate Principle implies his Absolute Principle – or at least that that the two principles never conflict.  That would be silly and dogmatic, but consistent.  Instead, Mill temporarily forgets his Ultimate Principle in favor of his Absolute Principle:

That 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 forbear
because it will be better for him to do so, because it will make him
, because, in the opinions of others, to do so would be wise, or
even right. (emphasis mine)

It gets worse.  Mill then admits big exceptions to his Absolute Principle:

[T]this doctrine is meant to apply only to human beings in the maturity of
their faculties. We are not speaking of children, or of young persons
below the age which the law may fix as that of manhood or womanhood.
Those who are still in a state to require being taken care of by others,
must be protected against their own actions as well as against external
injury. For the same reason, we may leave out of consideration those
backward states of society in which the race itself may be considered as
in its nonage… Despotism is a legitimate mode of government in
dealing with barbarians, provided the end be their improvement, and the
means justified by actually effecting that end.

Two pages, two “ultimate”/”absolute” principles, each with a big exception.  Whatever your views, this is awful philosophy.

The world is full of Mill fans, who will probably complain that I’m missing Mill’s fine and subtle distinctions.  But Mill’s distinctions just pile confusion on confusion.  Examples:

1. The definition of “utility”:

I regard utility as the ultimate appeal on all ethical questions: but it
must be utility in the largest sense, grounded on the permanent
interests of man as a progressive being.

But a man’s “own good, either physical or moral” surely includes his “utility in the largest sense.”  And Mill says that’s “not a sufficient warrant” for violating his liberty.

2. The role of discussion:

Liberty, as a principle,
has no application to any state of things anterior to the time when
mankind have become capable of being improved by free and equal

Unfortunately for Mill, neither his Ultimate nor Absolute Principles leaves any role for mere “capability.”  You could say, “If free and equal discussion will improve a person, you should respect his liberty.”  When words work, there’s no reason to resort to beatings.  But after free and equal discussion fails to open the eyes of a person capable of free and equal discussion, why not try coercion?  No matter what a person’s “capabilities,” Mill’s Ultimate Principle commands coercion and his Absolute Principle forbids it.

I freely admit that it would be easy to fix Mill.  Most obviously, he could keep his Ultimate Principle, explicitly demote his “Absolute” Principle to a mere rule of thumb, point out major counter-examples, then argue that people underestimate the negative effect of coercion on utility.  But this just proves my point: Mill wasn’t a good enough philosopher to notice and repair elementary flaws on adjacent pages.

P.S. If you think that Mill was a pretty good philosopher for his time, check out his critic James Fitzjames Stephen.  I’m in much closer agreement with Mill’s conclusions, but Stephen is a far superior philosopher.