Read the case State v. Ransom (pp. 411-425). Consider your verdict. Prepare a document that expresses your deliberation that justifies your vote of guilty or not guilty. The goal is not simply a w

8 The Burden of Proof

Listen to the Chapter Audio on mythinkinglab.com

The first step in critically analyzing an argument is determining the conclusion. The second step is determining who bears the burden of proof.

I claim that extraterrestrials have built an amazing undersea city, deep in the Pacific Ocean. They are mining natural resources from below the ocean floor, and transporting these resources back to their home planet through a fleet of interstellar cargo ships. You have doubts about the existence of this ET city, and challenge me to specify its location. I can’t, but I’m still sure it’s there. You ask for photographs of the city; I have none. Are there unusual findings from oceanographic research that would indicate the presence of such a deep sea metropolis? I have no such data. Are there any reliable witnesses who have seen the city? None. But I am firm in my claim: Look, the Pacific Ocean is vast and deep, and most of the ocean floor is unexplored. If you are so skeptical about the undersea city, then prove that it does not exist. And if you can’t prove that the ocean floor does not contain such a city, then that is strong evidence that such a city exists. At the very least, you should keep an open mind about the possibility of such a city, and put your skepticism aside.

Who Bears the Burden of Proof?

You aren’t likely to buy the existence of an ocean-bottom ET city as a result of this flimsy argument. There was no real proof for the claim, and anyone making a claim or an accusation bears the burden of proof. The person making the claim must prove it true; it is not up to others to prove it false. The fallacy of appeal to ignorance is committed when someone argues that because his or her claim cannot be proved false, it therefore should be accepted as true. But the fact that a claim cannot be proved false is no grounds for believing it true. (Certainly it does not prove that it is not true; it may be true, even though it is not proved so. But failure to prove a claim false is not proof of the claim’s truth.)

Attempts to shift the burden of proof are common. In 1988, television evangelist Pat Robertson made an unsuccessful run for president of the United States; during his

Placing the Burden of Proof

The “preliminary” question of who bears the burden of proof often has great influence on which side prevails in an argument. Suppose that I am a school district superintendent, and I impose a regulation requiring that teachers beyond the fourth month of pregnancy must take an unpaid leave of absence from their teaching jobs. You claim that this rule is unfair to women teachers, because it unreasonably deprives them of the opportunity to work. (There is no reason why most pregnant teachers cannot continue to teach effectively; some individuals may be incapacitated by pregnancy, but that should be decided on a case-by-case basis.) Does such a regulation treat women unfairly?

Before you answer that, think about the prior question: Who bears the burden of proof? You are claiming that my rule unfairly discriminates against women; is it up to you to prove that the rule places a special hardship on women? Or should the burden of proof be on me? After all, I proposed the rule; should it be my burden to prove that the rule does not unfairly discriminate?

That is a difficult question. The U.S. Supreme Court attempts to resolve it this way: If you want to claim that a law or rule treats you unfairly, then you generally have the burden of proving that unfairness; however, if you are a member of a group that has traditionally suffered discrimination and unfair treatment (such as women, African Americans, members of a persecuted religion, and the physically challenged) and you claim that the law treats members of your group unfairly, then those passing the law bear the burden of proving that it is not discriminatory. That seems to me a legitimate way of placing the burden of proof in such cases, though it is certainly a difficult issue. In any case, we can leave further discussion of that question for your seminar in Constitutional Law. The immediate point is that placing the burden of proof can be a very difficult question, and a very important question. When a pregnancy leave case came before the U.S. Supreme Court (Jo Carol LaFleur v. Cleveland Board of Education), the Court ruled on January 21, 1974, that the school board had failed to demonstrate that their pregnancy leave rule was not discriminatory toward women (a group that had traditionally suffered discrimination), and so struck down the rule. Women might well succeed in proving that such rules are discriminatory, even if they bore the burden of that proof; but with the burden on the other side to prove that the rule is not unfair, women teachers certainly had an easier path to victory.1

campaign he claimed that there were—or at least might be—Soviet missiles in Cuba. Since all indications—from spy satellites, for example—were that there were no such missiles, the question naturally arose as to what evidence the Reverend Robertson could offer for his dramatic claim. Having none, Robertson attempted to shift the burden of proof to the other side: His claims were supported by the fact that U.S. intelligence could not conclusively prove that no such missiles existed in Cuba. And of course Robertson was partly correct: Neither the U.S. intelligence service nor anyone else could conclusively prove that there were no Soviet missiles cleverly concealed deep in some Cuban cavern or

A Burden of Proof Tragedy

Placing the burden of proof may be a life or death question. The 1986 explosion of the Challenger spacecraft cost the lives of seven people. The accident was traced to problems with the O-rings, which did not function properly in the freezing weather at the time of the launch, allowing fuel to leak and thus causing the deadly explosion. Morton Thiokol was the company that manufactured the O-rings, and prior to the planned Challenger launch, engineers from Morton Thiokol raised the possibility of danger from the frozen O-rings. In the past, if anyone raised reasonable doubts about the safety of a launch, then there had to be solid proof that the supposed danger did not exist before the launch could proceed: The burden of proof was always on those who claimed that it was safe to launch. But in this case the presumption was reversed: The spacecraft was presumed to be safe, and anyone raising doubts had to conclusively prove that there was genuine risk in order to stop the launch. The Morton Thiokol engineers could show reasonable grounds for concern (the O-rings had not been tested in freezing conditions); but they could not demonstrate that the O-rings actually would malfunction in the cold and thereby cause an explosion. Since the burden of proof was (wrongly) placed on the engineers to prove danger rather than on the launch team to prove safety, the launch proceeded to its disastrous end.2

hidden in some other unknown—and unspecified—location. But that certainly does not substantiate Robertson’s claim, no more than the fact that we cannot prove that no brontosauruses live in caverns deep below New Orleans proves the existence of subterranean brontosauruses, and no more than the fact that we cannot prove that there are absolutely no extraterrestrials disguised as earthlings proves that we are in the midst of extraterrestrials. The person making the claim—of Soviet missiles, brontosauruses, or extraterrestrials—bears the burden of proof.

The sensationalist tabloids have a field day with the appeal to ignorance. They publish scandalous accusations concerning the lives and loves of movie stars and politicians and then—in support of those stories—they point out that: “Two weeks ago we published an exclusive story about Ima Starr’s torrid love affair with the Ambassador to Rutabaga; if it’s not true, they should deny it, but since they haven’t denied it, much less offered any proof that it is false, then it must be true.” But Ima Starr and the ambassador are caught in a bind: If they ignore the story, a few people will believe it, but most will ignore it and it will soon pass, since none of the major newspapers or television networks will consider the story reliable. However, if they deny the story, then that is news—whenever a film star and an ambassador issue statements, the press considers it newsworthy—and those denials (along with the charges being denied) will receive national news coverage, and the story will not blow over quickly. So even if there is not a grain of truth to the charges, it’s unlikely that a denial will be issued. And more to the point, it’s not up to them to prove the charges false (think for a moment of how difficult it would be to prove that you did not have a secret love affair with someone); the burden of proof rests on those making the charges.

A variation on this problem occurs when a snake oil salesman—for example, someone touting the miraculous healing powers of magnets—challenges the medical community to debate: “I’ve proposed that a panel of distinguished medical researchers and physicians examine the wonderful benefits of my Salumagnetomed System, and I’ve offered to meet with them anywhere and give my evidence; I challenge them to debate me! But they keep refusing!” So why won’t the AMA convene a panel to debate this wonderful new magnetic health system? For two reasons. First, such systems have already been examined carefully, and found to be useless; and if researchers took up every new variation of such quackery, they would have no time for legitimate research. And second, if a panel of “distinguished medical researchers and physicians” meet with this quack—even to roundly condemn it as fraud—he will immediately include it in his advertising, and it will greatly increase his credibility: “Try my new Salumagnetomed System, which was recently the focus of a full AMA-sponsored conference, drawing the attention of such distinguished researchers as...”; well, you get the picture. If legitimate scientists and physicians appear on the same platform with such quacks, it gives the quacks instant credibility: distinguished medical scientists believe it is worth taking this new magnetic therapy system seriously, and its inventor is seated on the same panel with legitimate scientists, just one top medical scientist among others.

There is a special setting in which it is vitally important to remember who bears the burden of proof, and in this setting—unfortunately—the fallacy of appeal to ignorance occurs with frightening regularity: the jury room. It is now a cornerstone of the American and British systems of criminal justice that a defendant is “innocent until proven guilty.” And in fact, the principle of “presumption of innocence” was already an essential element of English law when the earliest British settlers arrived in the American colonies, and thus it can be found in the earliest rules of legal procedure formulated by the British colonists in New England. The principle that the burden of proving guilt rests on the prosecution continued to be a feature of colonial American judicial procedure, even when (as in the witchcraft trials) courts were not particularly careful concerning the quality of “evidence.” This basic principle of justice is fundamental to the justice systems of many countries; for example, it is a prominent element of the Canadian Charter of Rights and Freedoms, it is a central principle of Australian Common Law (and part of the Victorian Charter of Human Rights and Responsibilities), and is one of the basic rights recognized in the 1789 French Declaration of the Rights of Man and of the Citizen.

Why is the “presumption of innocence” so important? First and foremost because it is simply the correct manner of reasoning. The burden of proof rightly belongs on the party that makes a claim, whether that claim is a pharmaceutical company’s claim that a new drug is “safe and effective” or a tabloid’s claim that extraterrestrials are hiding in Mammoth Cave or the state’s claim that an individual committed a crime. If the proof can be supplied, fine; but failure to either prove or disprove the claim is just that: a failure to prove anything, which leaves the safety of the drug in doubt and the guilt of the defendant unestablished.

There is a second reason why the burden of proof lies with the one making the claim. If one were allowed to “appeal to ignorance” (appeal to the failure to disprove the claim) in order to “prove” a claim, then one would be able to “prove” the most extraordinary things. For example, it is quite impossible to prove that there is not a group of invisible extraterrestrials lurking in the depths of the Indian Ocean, but we should be loath to count that as proving the presence of such beings. It is not possible to prove that Rousseau never had a very secret love affair with Marie Antoinette, but lack of disproof of such an affair does not prove that such a tryst occurred. More to the point, imagine trying to prove that you are innocent of a murder that occurred at 11:00 p.m. 3 years ago. Unless you keep a remarkably good diary, you probably don’t have an exact recollection of where you were at that time, much less a convincing alibi. (Even if you distinctly remember being in the college library with a friend all that evening, will your friend remember it? And will your friend be absolutely certain that you didn’t leave—for perhaps half an hour around 11:00 p.m.—just long enough to commit the foul crime of murder?) In fact, if failure to disprove the charges were counted as proof of those charges, then we would never have an unsolved crime: Almost any crime that occurred could be “proved”—by appeal to ignorance—against some unfortunate reclusive individual who was not seen by anyone during the time of the crime. Such appeals to ignorance certainly have advantages: They have (to borrow Bertrand Russell’s phrase) “all the advantages of theft over honest labor.”

There is another reason for favoring a strong presumption of innocence. It has less to do with logic and more with our principles of individual freedom and justice. We believe that the rights and freedom of the individual are fundamental, and we oppose sacrificing individual rights and autonomy for the benefit of the state; therefore, the general presumption must be that the individual’s rights and freedom should not be interfered with. Any denial of individual liberty (through criminal sanctions) requires powerful overriding reasons and the strongest and most conclusive proof. Placing the burden of proof on the defendant violates principles of liberty as well as logic. Unfortunately, jurors often reverse the burden of proof. Dr. Stanley Brodsky tells of a jury questionnaire he gave to potential jurors prior to a murder trial in Kentucky. One of the questions was, “No matter what the law says, do you agree that a defendant in a murder trial should have to prove his innocence?” Over 40% of the potential jurors marked their agreement with requiring the defendant to prove innocence—and it is likely that there were others who agreed but were reluctant to admit it.

What is involved in the “presumption of innocence” for the defendant? Most obviously, the defendant does not have to prove anything. The full burden of proof rests on the prosecution, and if the prosecution leaves a reasonable doubt after the presentation of its case, the defense need do nothing at all. And if the prosecution has managed to make a strong argument for the guilt of the defendant, the defendant need not totally shatter that argument; instead, the defense need only show that the prosecution’s argument is not quite convincing. The defendant need not establish his or her innocence. Unless the prosecution can build a case that both firmly establishes the defendant’s guilt and withstands all attempts by the defense to raise doubts about the case, the jury should conclude that the prosecution has not proved its case and should therefore vote not guilty.

The presumption of innocence is a basic principle of logic and of Anglo-American criminal law. But jurors sometimes forget the principle: They reverse the order and demand that the defendant “prove he’s not guilty” or “clear herself of the charges.” And there is a more subtle way in which mistakes are made about the burden of proof in criminal proceedings. When the defendant does not testify in his or her own behalf, many jurors weigh that very heavily against the defendant. But the defendant has no obligation to testify. It is not the responsibility of the defendant to prove innocence: The full burden of proof rests on the prosecution.

The fallacy of appeal to ignorance is at home in the supermarket tabloids and scandal sheets, but it occasionally shows up in more respectable settings. In Sacco & Vanzetti: The Case Resolved, Francis Russell argues that Nicolo Sacco was in fact guilty of the crime for which he was executed. (The Sacco–Vanzetti case is perhaps the most famous—or infamous—American criminal case in the twentieth century. In 1920, in South Braintree, Massachusetts, two gunmen shot and killed a paymaster and guard and stole a payroll. Nicolo Sacco and Bartolomeo Vanzetti were both active in the anarchist political movement and were thus mistrusted by the authorities. They were arrested and—largely on the basis of some rather shaky eyewitness testimony—were convicted of murder. They were electrocuted on August 27, 1927, still steadfastly asserting their innocence.) One of Russell’s arguments for the guilt of Sacco is the following (it is contained in a letter Russell wrote to Dante Sacco, the son of the man who was executed):

I cannot look on him [Nicolo Sacco] as an innocent man. I may be wrong. So much has always been indeterminate in this case. Yet in the silence of the Sacco family is, at least to outsiders, an implication of guilt. That is the only conclusion that I can draw.3

The fact that the son of the executed man refused to comment on the case proves nothing at all. Certainly it carries no implication that Dante Sacco agrees that his father was guilty of murder. No matter what reason Dante Sacco had for remaining silent, his silence is not proof that his father was guilty. To suppose that silence proves guilt (to suppose that silence proves anything) is to commit the fallacy of appeal to ignorance. In fact, you can no doubt think of several excellent reasons why Dante Sacco would remain silent even if he believed his father innocent.

First, Dante Sacco was only 7 years old when his father was arrested. Even if he believed his father was innocent, it is not likely that he would have any strong evidence to that effect, and he might have thus decided to keep silent.

Second, Dante Sacco was perhaps traumatized by the electrocution of his father—it’s not difficult to imagine that being the effect on a 15-year-old boy—and thus could never again bear to think of the events, much less publicly speak about them.

Third, perhaps Dante Sacco wanted to get on with his own life and put the past behind him, and thus preferred not to be associated with past events. (There could be some social stigma attached to being in the family of a famous anarchist, and Dante may have wanted to avoid such social pressures.)

Fourth, Dante may have kept silent from his desire to spare his own family, including his children, from social pressure and stigma.

And finally, if Dante Sacco believed his father was innocent and had been murdered because of his political views—which is what his father claimed—then Dante might have had good reason to be fearful of speaking out against such injustices.

Perhaps those are, perhaps they are not, the real reasons why Dante Sacco remained silent concerning the execution of his father. In any case, the moral of the story is this: Silence is not proof, one way or the other.

U.S. and Canadian courts recognize that the defendant has no obligation to testify on his or her own behalf, and judges in both countries are careful to remind jurors that the decision of a defendant not to testify in no way counts against the defendant. But all too often the defendant’s decision not to testify does create a presumption against him, due to the fallacious reasoning of some jurors. Jurors are apt to think that “He didn’t clear himself of the charges so he must be guilty” or “If he were not guilty he would want to take the stand and deny the charges, so he must be guilty.” Or perhaps they continue to give lip service to the principle that the defendant need not testify, but in their actual deliberations they may still count the defendant’s nontestimony against the defendant. But that is pure appeal to ignorance: He hasn’t proved the charges false, so they must be true.

Until the end of the nineteenth century, defendants in British criminal cases were not allowed to testify in their own behalf. The Criminal Evidence Act of 1898 gave the defendant the right, if he or she chose, to be placed under oath and give testimony. There are many obvious benefits to such a change, and no doubt it is on the whole a

great improvement in trial procedure and a salutary extension of the rights of the individual. However, it is by no means an unmixed blessing: Once given the right to give testimony on their own behalf, jurors started to expect defendants to take the stand and deny their guilt; and if the defendant did not testify, jurors often switched the burden of proof—“the defendant would not even deny the charges against him, so he must be guilty”—and counted the failure of the defendant to testify and to establish his innocence as proof of guilt. The right of a defendant to testify is an important right; but if jurors interpret that right as an obligation to testify, or as an obligation that defendants prove themselves innocent, then that right has become a terrible wrong which can and does result in wrongful convictions.

And after that act there was also a danger that by not going into the witness box the defendant might lead the jury to conclude that the defendant is unable to establish innocence, and that is an equally mistaken version of misplacing the burden of proof and committing the fallacy of appeal to ignorance.

Consider where the burden of proof lies in this fictional example of a jury debate.5 The defendant is charged with the criminal possession of a prohibited drug. Two arresting police officers testify that they chased and caught the defendant, took him to the police

When a juror assumes that the defendant must prove innocence, the juror obviously has misplaced the burden of proof. But there are more subtle ways of shifting the burden of proof against a defendant. Imagine that you are called for jury duty, and the case involves serious criminal charges (such as murder). You are of course committed to the principle that the prosecution bears the entire burden of proving the defendant’s guilt beyond a reasonable doubt, and you start from the presumption that the defendant is innocent. Before you are seated on a jury, however, the prosecution asks the judge for a special ruling to keep the names of all potential jurors a secret and to have all potential jurors escorted from the courthouse each day by armed federal marshals. What conclusion is a juror likely to draw from such special “protection”? As William M. Kunstler has pointed out, jurors will conclude that the “defendant is so far beyond the pale that their very lives would be in danger if their identities were made public.” Such a conclusion, prior to hearing any evidence, effectively torpedoes any “presumption of innocence.” In an article in the Fordham Law Review, Abraham Abramovsky discussed the problems such policies pose for the presumption of innocence:

In effect, by his instruction with respect to anonymity, the trial judge implied that the defendants were so vicious and dangerous that anonymity was required to protect the jurors and their families from harassment, physical injury or even death. In any prior jury service, the jurors would not have been instructed to remain anonymous. Therefore the only reasonable inference that a jury could draw ... was that protection was mandated by the character of the defendant. ... Thus, before any evidence was introduced ... the defendants were depicted by implication as notorious individuals. This characterization ... eviscerated the presumption of innocence to which these defendants were entitled.

If such anonymity were really essential to protect jury members, we would be faced with a tough choice between protecting the safety of jurors and protecting the defendant’s right to the presumption of innocence and to a fair and unbiased trial. But as Kunstler noted, “To my knowledge, during the more than 200 years of this Republic’s existence, no juror has ever been harmed by a defendant or his or her supporters.”4

The “right to remain silent” is closely linked to the presumption of innocence: If you are charged with a crime, you have a right to remain silent (and cannot be compelled to testify), because the burden of proof rests entirely on the prosecution, and you are not required to say or do anything to establish your innocence. The right to remain silent was a cornerstone of the British judicial system, and it became firmly entrenched in the legal systems of countries—such as Canada, Australia, and the United States—that were deeply influenced by the British model of justice: the right is recognized in the Fifth Amendment to the U.S. Constitution (as one of the Bill of Rights) and is protected under sections 7 and 11 of the Canadian Charter of Rights and Freedoms. In the United States, the first words of the Miranda warnings are “You have a right to remain silent.” That is the warning given to all who are arrested, a warning that is a staple of every episode of Law and Order, and a basic principle of justice. Indeed, the right to remain silent has been widely recognized as fundamental to human rights and to procedural justice: The European Court of Human rights holds that “The right to remain silent under police questioning and the privilege against self-incrimination are generally recognised international standards which lie at the heart of the notion of a fair procedure.” Sadly, that right is under attack in the place of its birth: the British justice system. The Criminal Justice and Public Order Act of 1994 permits the accused to remain silent, but also permits the judge to instruct the jury that the jurors may “draw adverse inferences” from the fact that a defendant chose not to answer questions or chose not to testify; that is, the judge can instruct the jury that they may conclude that because the defendant did not testify, that can be counted as some evidence of the defendant’s guilt. Under this law, juries are not supposed to convict the defendant solely on the basis of the defendant’s silence; but if there is other evidence against the defendant, then the defendant’s silence can tip the scales toward conviction. There has been strong opposition to this law since its passage, and some British politicians who support the law have claimed that the law does not undercut the basic right to silence: you still have a right to remain silent, though if you exercise that right you will be more likely to be convicted and imprisoned. But that is absurd. It’s like saying, “You have a right of free speech; but if you speak freely, you run a greater risk of being imprisoned.”

station, but did not find the drug on the defendant. The police then (so they testified) returned to the scene of the arrest and found a packet of tablets of the prohibited drug, which (the police claimed) the defendant had thrown away when he was caught. The defendant denies ever having possessed the drugs and denies any knowledge of the tablets. After long discussion, the members of the jury agree (rightly or wrongly) that someone placed the drugs where they were found, and that it must have been either the defendant (who threw them there) or the police (who planted them in order to “prove” the defendant guilty). At this point an argument develops, and one member of the jury argues thus:

Look, the question comes down to this: Do we believe the testimony of the policemen or the testimony of the defendant? It seems to me quite possible that the defendant is telling the truth, and the policemen are trying to frame him. However, it certainly seems more likely that the defendant is lying and the policemen are telling the truth. Since we have to believe one or the other, it seems only reasonable to accept the most likely story, and since the police story is the more likely to be true, we ought to accept it. And if we accept the police account, obviously we must find the defendant guilty.

What do you think of that argument? How would you explain what is wrong with it to your fellow jurors?

If it were only a question of which position is more plausible, then it might be an effective argument. That is, if it were a question of deciding whether it is more likely that the defendant discarded the drugs at the scene of the arrest or that the police planted them, then perhaps the police account is more likely. But that is not the question. Framing the issue that way misplaces the burden of proof. Instead of the burden of proof resting squarely on the prosecution (where it belongs), the argument places it equally on the prosecution and the defense. The proper question is not which side appears more plausible; rather, the question is whether the prosecution proved its case beyond a reasonable doubt. Even if you agree with the juror that the police story is more likely to be true, that is far from sufficient. It is not enough for the prosecution to establish that its case is more plausible; rather, the prosecution must prove beyond a reasonable doubt that its account of the defendant’s guilt is true. The defense need not show that its version of the events is more likely to be true than the version given by the prosecution; instead, the defense need only show that there is a reasonable doubt that the prosecution’s case is true. Whenever a claim is made—that an artificial sweetener is safe, that an arthritis remedy is effective, that an individual is guilty of a crime—the burden of proof rests on those making the claim. “Share and share alike” may be excellent advice in some contexts, but it is poor logic and fallacious reasoning when trying to locate the burden of proof.

Consider the Verdict

This case occurred in 2002, in Pennsylvania. Jennie Collins went to a party, where she drank what tasted like (and what she claimed she believed to be) fruit punch. She left the party and drove to the residence of a friend, Megan Neff. There she complained of a headache, then became silent. Jennie and Megan then left together to go to the home of another friend, with Jennie driving. Jennie drove past the friend’s home, drove through several stop signs without stopping, and then swerved into oncoming traffic. Jennie then braked the car while Megan steered it off the road. Jennie lost consciousness, and when the police arrived she was slumped over the wheel. An ambulance was called, and Jennie screamed at and fought the ambulance workers. She was taken to the hospital, and there she tested positive for PCP.

Jennie Collins was charged with driving under the influence of a controlled substance, and a jury found her guilty. In her defense, Jennie had agreed that she was driving under the influence, but argued that her intoxication was involuntary. The judge instructed the jury that the burden of proving involuntary intoxication rested on the defendant, and that she had to prove by a preponderance of the evidence that her intoxication was involuntary. (She was not required to prove beyond a reasonable doubt that her intoxication was involuntary; but the judge ruled that she still had the burden of proof: of establishing involuntary intoxication by a preponderance of the evidence. That is, she must convince the jury that it is more likely than not that her intoxication was involuntary; the prosecution must prove that she operated a vehicle while intoxicated, but does not have to prove that her intoxication was voluntary.)

The jury returned a verdict of guilty. Jennie Collins appealed her conviction, arguing that the trial judge erred in his instructions, that her presumption of innocence was violated, and that the burden of proving voluntary intoxication should rest on the prosecution.

As an appeals court judge, the case now comes to you. How do you rule?6

Unappealing Ignorance

A word of caution. Appeals to ignorance do occur with depressing regularity, but be careful that you don’t start seeing the fallacy when it’s not really there. The fallacy of appeal to ignorance is a very specific fallacy: It occurs only when one argues that a claim is true because it has not been proved false. Not all ignorant statements and stupid arguments commit the fallacy of appeal to ignorance. If I claim that evil spirits cause sickness, that will reveal my profound ignorance of modern medicine; it is not, however, the fallacy of appeal to ignorance unless I argue that evil spirits must cause sickness because no one has been able to conclusively prove that evil spirits are not the cause of sickness. If I assert that invisible martians live in the sewers under New York City, you may well be justified in concluding that I am an ignorant—perhaps completely batty—individual, but you would be wrong to charge me with the fallacy of appeal to ignorance, for I am not appealing to ignorance. I may be ignorant, and that is unfortunate, but it is not a fallacy. In order to commit the fallacy of appeal to ignorance, I must actually make that appeal: I would have to argue that there are invisible martians in the New York sewers because no one has been able to prove that there are none.

So not all claims made in ignorance commit the fallacy of appeal to ignorance. On the other side of the coin, a person may commit the fallacy of appeal to ignorance without being an ignorant person. Intelligent and knowledgeable persons may easily become confused about where the burden of proof belongs on some particular issue and thus may commit the fallacy of appeal to ignorance. To avoid that fallacy, keep a careful watch on exactly what conclusion is being claimed and who is making the claim. Whoever makes the claim, brings the accusation, or asserts the theory bears the burden of proving it true.