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On Liberty | Chapter 2 : On the Liberty of Thought and Discussion | Summary



Mill begins Chapter 2 by explaining that freedom of the press is a well-established principle of democracy. What concerns Mill, however, is a democratic government, acting in accordance with the will of the people, that limits the free speech of a minority. He very clearly calls this power "illegitimate," and he denies "the right of the people to exercise such coercion, either by themselves or by their government." The grounds for his denial are completely utilitarian, arguing not for the sanctity of any individual rights or rights to solely private opinions but because silencing an opinion robs "posterity as well as the existing generation" of the benefit of open exchange. This, Mill contends, is true regardless whether the content of the speech is "right" or "wrong." If right, society obviously loses the benefit of the truth; if wrong, people lose the benefit of improving and clarifying their position of the truth through open debate.

The remainder of the chapter is left to defend these two positions. (Mill later splits the second position into two similar points on the same theme.) On the first defense of free thought and expression, that an offending position is true, Mill finds that there is no authority that can justify its censure. Such a power would have to be "infallible" or act with "absolute certainty," either of which is not possible. To the objection that Mill's argument of infallibility could be applied to any action, that there is always a level of uncertainty and that that uncertainty should not block normal activity, Mill responds that this is so, but that silencing speech precludes the possibility of action, that it is by silencing speech that sets an absolute closure on action. He writes, "complete liberty of contradicting and disproving our opinion ... is the very condition which justifies us in assuming its truth for purpose of action." In short, Mill says by silencing speech action is foreclosed; the act of censorship is not an action but the negating of an action.

Mill then entertains a series of questions posed as counterarguments. First he tackles the question of what brings about human progress and the refinement of human ideas from a long history of "erroneous" conclusions from the past. What is the source of human wisdom? Mill finds that wisdom is not developed in a vacuum but is part of a process of studying and considering as wide a scope as possible of thought and opinion on a given topic. Next he asks whether some ideas are not necessary to the very functioning of governance; if so, they should not be questioned or they should not be allowed to be challenged. But Mill finds this is an argument based on the usefulness of an idea or opinion and that "the usefulness of an opinion is itself matter of opinion" and not free from the logic of considered engagement that he advocates above. Therefore, no idea fundamentally "useful" to the practice of governance is outside the realm of open debate.

The chapter then engages questions of ideas that truly are certainties, for example, principles of human morality or belief in God. Again, Mill finds that while these principles may be universally true, to limit the freedom of engagement on the question is to deny others the ability to decide for themselves. Furthermore, it is certainty that is at the root of some of the most egregious mistakes of history. By way of example, Mill recounts the trial and execution of Socrates for impiety and corruption of the youth, essentially, for ideas. Yet 1,800 years of history have condemned the Athenian state for the certainty with which they killed Socrates as one of the great and tragic injustices of history.

Another example he gives is of Marcus Aurelius (121 CE-180), an ideal Christian in all but name, who persecuted Christians, believing their religion to be false, before Christianity was made the official state religion under Constantine. Shifting gears, Mill argues that those who say truth ultimately wins out over falsehood are mistaken. History shows that persecution often effectively squelches truth. It is true: society no longer executes heretics, but social ostracism and marginality can be an equally effective measure for silencing dissent. In the social environment in which heretical ideas are silenced, it is not the heretics who primarily suffer. Instead, the great loss is to society. Individual great thinkers may be produced in environments of conformity, but more important is an atmosphere that can create an "intellectually active" population in general. In those conditions great ideas are produced through the process of exchange and debate.

Mill then turns to the second of his conjectures: that even if it's false, a contrary idea should receive full freedom because it contributes to the process of refining and improving truths more widely accepted. In this way ideas are prevented from becoming a "dead dogma" so they can thrive as a vibrant "living truth." Indeed, truths not rigorously debated and engaged become like another "superstition," accepted without question, rather than continually tested for their veracity.

To the question that people can be taught to have correct opinions like they are taught geometry or mathematics, Mill argues this is a faulty comparison. Mathematics has but one definitive answer. Problems of human society and discourse are not so simple: there are often conflicting positions, all with elements of truth, which can be rectified only through open exchange. Indeed a person familiar with only one side of an argument is not truly acquainted with its full reasoning. For that, other positions must be explored and refuted. Some may argue that open debate is indispensable for philosophers and theologians but unnecessary for common people. Mill counters that to limit freedom of expression for some is to limit freedom of expression for all, and that without full and open debate at all levels of society even the learned suffer for want of stimulus.

Ideas lose their vitality through lack of debate, and Mill explores this central idea of the chapter through several examples. Most religious doctrines have grown and flourished in an atmosphere of intellectual debate. In this time of constant contestation a true position will gain adherents, and as it grows in acceptance, it becomes challenged less and less. As a result the position is accepted without thought or reason and loses its vitality, becoming a "hereditary creed" without much thought. This can be seen in Christians who profess a belief in the tenets of Christianity but behave very differently. For them "the sayings of Christ coexist passively in their minds, producing hardly any effect beyond what is caused by mere listening to words so amiable and bland." Taking on another question, Mill asks whether doubt and debate are necessary for truth and whether, once established, truth is uncontestable. Indeed debate is necessary, he finds. For example, the Socratic dialogues remain so fresh for us today because they are argued through "negative" position in the form of a dialogue.

Mill now introduces a third justification for the defense of free thought and speech. He argues that orthodox and heretical opinion both contain elements of truth, to greater or lesser degrees, even though people have a tendency to view issues "with exclusiveness," that is, one-sided issues in black and white. Instead, Mill argues, "the nonconforming opinion is needed to supply the remainder of the truth, of which the received doctrine embodies only a part." Hence in politics and other human affairs, parties of "order" and of "progress" are both necessary. Some may object, for instance, that Christian doctrine provides the complete and definitive truth on questions of morality. Mill argues that even this doctrine presupposes a moral order independent of itself. Furthermore, the process of defining truth came through edits, changes, and refinements, open debate and exchange. For example, Christian teaching lacks notions of public-minded governance found in the Koran, or the "high-minded" humanism of the ancient Greeks or Romans. Mills argues that the books of the Bible "contain, and were meant to contain, only a part of the truth."

Mill concludes the chapter with a summary of his main points, and a discussion of "intemperance" of speech. For those who argue that invective or ad hominem have no place in reasoned discourse, Mill says that while this may be so, accusations of intemperance are often politically motivated, so insurgent ideas often face the brunt of accusations of intemperance or lack of fair discussion, usually as a way to silence debate. Therefore, even the manner in which debate progresses should not be silenced or limited.


Chapter 2 is the longest chapter in the book because it establishes a number of points that Mill uses in later chapters. First, he explores the full scope of free thought and discussion, arguments for and against, by way of showing that there is very little justification ever for acting to silence speech or thought. "Thought and discussion" are used here as an example that Mill then uses to justify much larger issues of personal freedom. Establishing one goes a long way to establishing and justifying other forms of individual liberty. Mill therefore puts only one limit on expression—that which causes harm to others—and spends the entire chapter arguing why no justification based on content can suffice to limit thought or expression. Mill's use of freedom is both protective (in that it seeks to limit government or social action to protect the individual) and active (in that the scope of individual activity in regard to this freedom should be as broad as possible). Mill explores the proper limit to these freedoms in a later chapter and here only discusses the justification for an expansive freedom.

Mill also establishes other foundations in this chapter that are important later in the work. One is his argument from "utility" rather than from rights. In this, Mill's distance from the Enlightenment concept of rights is the clearest. His argument is that speech and thought are not "rights" inherent to the human condition that should be honored as inviolable and sacrosanct. Instead, open debate and discussion benefit all of society, dissenting individuals included, and on that basis Mill mounts his defense. This point is important because Mill then has to demonstrate how debate and openness produce better results. To do so he relies on a notion of objective "truth" that debate helps clarify and provides numerous examples and counterarguments. By clarifying truth in this way all of society may benefit. This introduces another important principle from this chapter: the notion of singular or progressive truth. Mill's argument is that "truth" can be revealed only in exchange; that no one person, institution, or set of ideas is infallible; and that debate and discussion are essential to the process of the refinement of truth.

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