One Very Simple Principle
Mill's harm principle, tested on the cases he discusses himself.
Mill says the object of his essay is to assert one very simple principle. The only purpose for which power may rightly be exercised over any member of a civilized community against his will is to prevent harm to others. His own good, physical or moral, is not a sufficient warrant. Over himself, over his own body and mind, the individual is sovereign.
In the later chapters of the book Mill tests the principle on hard cases. Here are sixteen of them, all his own examples, one at a time. For each, decide how far society may go. Mill's answer appears once you choose, and at the end you can see where you and he part.
Society may: leave it alone; disapprove, warn or avoid, which Mill counts as the exercise of others' own liberty and not as a penalty; regulate or refuse to enforce, short of forbidding; or compel, forbid or punish.
Someone has shared their answers with you. Answer the cases yourself. Theirs appear under each case once you have chosen, and beside yours in the chart at the end.
Where you and Mill part
Each row is a case. The filled mark is Mill's answer and the hollow mark is yours. Marks to the right mean more interference.
What the principle rests on
Mill does not rest the principle on abstract right. He says he regards utility as the ultimate appeal on all ethical questions, but utility in the largest sense, grounded in the permanent interests of man as a progressive being. The case for liberty is that individuality, variety of character and experiments in living are elements of human well-being, and that a society which crushes them in the name of custom stagnates.
He limits the principle to adults in what he calls civilized societies. Children are excluded, and so, explicitly, are peoples he considered backward, for whom he says despotism is a legitimate mode of government if its end is their improvement. Readers who take the principle as a universal statement of rights have to reckon with that passage.
Some of the answers above surprise modern readers in both directions. Mill defends the drunkard, the polygamist and the eater of pork against the majority. He also allows laws against marrying without means and requires that every child be educated, and he would refuse to enforce a man's contract to sell himself. What decides each case for him is whether others are harmed. Whether the result looks lenient or strict does not enter into it.
All sixteen cases, with Mill's answers
1. Drunk at home. A man drinks himself senseless at home most nights. He lives alone and has no dependants.
Mill: disapprove, warn, avoid. Others may think less of him, warn him and keep away from him. That is their liberty, not a punishment. He harms no one but himself, so the law has no business with him.
Chapter 42. Policeman on duty. A policeman is drunk while on duty.
Mill: compel, forbid, punish. No one should be punished simply for being drunk, but a soldier or a policeman should be punished for being drunk on duty. Once there is definite damage, or a definite risk of damage, to others, the case leaves the province of liberty and enters that of law.
Chapter 43. Violent drunkard. A man once convicted of violence committed while drunk is found drunk again.
Mill: compel, forbid, punish. He may be placed under a special legal restriction, so that being drunk at all makes him liable to a penalty, heavier if he offends again while drunk. For a man whom drink makes violent, getting drunk is a crime against others.
Chapter 54. Unsafe bridge. A stranger is about to step onto a bridge known to be unsafe. There is no time to warn him.
Mill: compel, forbid, punish. A public officer, or anyone, may seize him and turn him back. This does not really infringe his liberty, since liberty is doing what one wants, and he does not want to fall into the river. Where there is only a risk and time to warn him, he should be warned and left to decide for himself.
Chapter 55. Arsenic. A shop sells arsenic, which can kill rats or a husband.
Mill: regulate or refuse to enforce. Forbidding the sale would burden every innocent use. The state may require the seller to register each sale: the buyer's name, the quantity and the stated purpose. Misuse can then be traced without preventing use.
Chapter 56. Selling oneself. A man signs a contract selling himself into slavery.
Mill: regulate or refuse to enforce. The state should decline to enforce the contract. In selling himself he gives up any future use of his liberty, which defeats the very reason for letting him dispose of his own lot. The principle of freedom cannot require that he be free not to be free.
Chapter 57. Gambling house. A man keeps a house where others come to gamble.
Mill leaves it open. Mill leaves this case open. Gambling itself should be free. The man who profits by encouraging it is harder, and Mill sets out the arguments on both sides without deciding between them. He suggests such houses might be tolerated but made to operate out of public view, known only to those who seek them.
Chapter 58. Idle father. Through idleness, a father fails to support his children.
Mill: compel, forbid, punish. He may be compelled to fulfil the obligation, by compulsory labour if nothing else will serve. He is punished for failing in a duty to others, not for being idle.
Chapter 59. Public indecency. Two adults do something in public that would be harmless in private but offends against decency.
Mill: compel, forbid, punish. Acts that harm only those who do them may be forbidden when done publicly. They are then violations of good manners and fall among offences against others.
Chapter 510. Pork. In a country where most people are Muslims, the majority votes to forbid anyone to eat pork.
Mill: leave it alone. This is Mill's own example. The majority's disgust is sincere, but the conduct concerns only those who engage in it. He calls the law an illegitimate interference with individual liberty.
Chapter 411. Polygamy. A religious community that has withdrawn to a remote territory practises polygamy, with the consent of all parties.
Mill: disapprove, warn, avoid. Mill finds the institution repugnant: a riveting of the chains of one half of the community. But the parties consent, and they have withdrawn to a remote place they were the first to make habitable. Others may send teachers to argue against it. They may not suppress it.
Chapter 412. Prohibition. A state forbids all sale of alcohol.
Mill: regulate or refuse to enforce. Mill treats prohibition as a violation of liberty: it restrains the seller in order to restrain the buyer. The state may tax drink for revenue and may license and regulate the houses that sell it for the sake of public order. It may not forbid it.
Chapters 4 and 513. Schooling. Parents refuse to have their child educated.
Mill: compel, forbid, punish. The state should require that every child be educated, fine the father who fails, and check the result by public examinations. It need not run the schools. Mill fears a single state education that would mould everyone alike.
Chapter 514. Marriage, no means. A couple with no means of supporting a family want to marry.
Mill: compel, forbid, punish. Laws on the Continent forbidding marriage unless the parties can show the means of supporting a family do not, Mill says, exceed the legitimate powers of the state. To bring a child into the world without a fair prospect of feeding and educating it is an injury to others.
Chapter 515. Corn dealer: print. A newspaper article argues that corn dealers starve the poor.
Mill: leave it alone. The opinion may be false and inflammatory, but circulated in the press it should be left free.
Chapter 316. Corn dealer: mob. A speaker says the same thing to an excited mob gathered outside a corn dealer's house.
Mill: compel, forbid, punish. The same opinion may justly be punished here. The circumstances turn its expression into a positive instigation to a harmful act.
Chapter 3