關於愛，我是個小學生。

John Stuart Mill (From Wikipedia, the free encyclopedia)
Born 
20 May 1806 Pentonville, London, England
Died 
8 May 1873 (aged 66) Avignon, France
Era
19th-century philosophy, Classical economics
Region 
Western Philosophy
School 
Empiricism, utilitarianism, liberalism
Main interests 
Political philosophy, ethics, economics, inductive logic
Notable ideas 
Public/private sphere, hierarchy of pleasures in Utilitarianism, liberalism, early liberal feminism, harm principle, Mill's Methods

John Stuart Mill FRSE (Fellow of Royal Society of Edinburgh) (20 May 1806 – 8 May 1873) was an Anglo-Scottish philosopher, political economist and civil servant. An influential contributor to social theory, political theory, and political economy. He has been called "the most influential English-speaking philosopher of the nineteenth century"[2] Mill's conception of liberty justified the freedom of the individual in opposition to unlimited state control.[3] He was a proponent of utilitarianism, an ethical theory developed by Jeremy Bentham. Hoping to remedy the problems found in an inductive approach to science, such as confirmation bias, he clearly set forth the premises of falsification as the key component in the scientific method.[4] Mill was also a Member of Parliament and an important figure in liberal political philosophy.

On liberty
Introduction 
Mill opens his essay with a discussion about the "struggle between authority and liberty" describing the tyranny of government, which, in his view, needs to be controlled by the liberty of the citizens. Without such limit to authority, the government has (or is) a "dangerous weapon". He divides this control of authority into two mechanisms: necessary rights belonging to citizens, and the "establishment of constitutional checks by which the consent of the community, or of a body of some sort, supposed to represent its interests, was made a necessary condition to some of the more important acts of the governing power". As such, Mill suggests that mankind will be happy to be ruled "by a master" if his rule is guaranteed against tyranny. Mill speaks in the aforementioned section in terms of monarchy. However, mankind soon developed into democracy where "there was no fear of tyrannizing over self". "This may seem axiomatic", he says, but "the people who exercise the power are not always the same people with those over whom it is exercised". Further, this can only be by the majority, and if the majority wish to criminalize a section of society that happens to be a minority — whether a race, gender, faith, or the like — this may easily be done despite any wishes of the minority to the contrary. This, in his terms, is the "tyranny of the majority".
In Mill's view, tyranny of the majority is worse than tyranny of government because it is not limited to a political function. Where one can be protected from a tyrant, it is much harder to be protected "against the tyranny of the prevailing opinion and feeling". People will be subject to what society thinks is suitable — and will be fashioned by it. The prevailing opinions within society will be the basis of all rules of conduct within society — thus there can be no safeguard in law against the tyranny of the majority. Mill goes on to prove this as a negative: the majority opinion may not be the correct opinion. The only justification for a person's preference for a particular moral belief is that it is that person's preference. On a particular issue, people will align themselves either for or against this issue; the side of greatest volume will prevail, but is not necessarily correct. 
According to Mill, there is only one legitimate reason for the exercise of power over individuals:
 "That the only purpose for which power can be rightfully exercised over any member of a civilised community, against his will, is to prevent harm to others."
This is the first mention in On Liberty of the harm principle. The only limiting factor of liberty in Mill's view should be harm in the form of either physical or moral compulsion. If a person is thus harmed, then his or her sovereignty over self is impaired because sovereignty is exercised either through action or judgement. Children and those who cannot take care of themselves are allowed to be interfered with beyond the harm principle as they may well harm themselves unintentionally; they do not, and cannot, have sovereignty over self. Furthermore, Mill states that one may accept despotism over "barbarians" if the end result is their betterment; this implies that barbarians are of "nonage" and cannot be sovereign over self. As soon as people are capable of deciding for themselves, they should then be given liberty from authority. To illustrate his point, Mill uses Charlemagne and Akbar the Great as examples of such compassionate dictators who controlled and supposedly helped "barbarians". 
At this point, Mill divides human liberty when in private into its components or manifestations:
 The freedom to think as one wishes, and to feel as one does. This includes the freedom to opinion, and includes the freedom to publish opinions known as the freedom of speech,
 The freedom to pursue tastes and pursuits, even if they are deemed "immoral," and only so long as they do not cause harm,
 The "freedom to unite" or meet with others, often known as the freedom of assembly. 
Without all of these freedoms, in Mill's view, one cannot be considered to be truly free.

"We can never be sure that the opinion we are endeavoring to stifle is a false opinion; and if we were sure, stifling it would be an evil still." ~ On Liberty Ch. 2