schrodingers cat
29th December 2011, 12:50
Dear old KiwiBiker. How we love to fight and moan.
Just thought I might post this so you don't enter the next stoush with your pants down. Or the spectators might enjoy spotting the common mistakes
Enjoy
Following are some of the most common logic faults. Whenever appropriate, both the common name and the Latin terminology are used:
1. Argumentum Ad Hominem (argument against the person)
This is the personal attack, probably the No. 1 logic fault you will find in opinion pieces everywhere. The ad hominem argument ignores the issue altogether and tries to discredit the person holding the idea. You once were able to discredit almost any idea by saying it was a "communistic idea." And in the political debates of today you can hear similar tactics. Liberal friends of President Clinton said he was wrong to push for the North American Free Trade Agreement and the General Agreement on Tariffs and Trade because so many Republicans were for it and they couldn't be right. And some conservatives berated the Republican support for NAFTA and GATT because "everybody knows" whatever Clinton is for must be wrong. There are a great many people these days who are against whatever Rush Limbaugh is for, for anything Richard Gephardt is against. Our views of Democrats or Republicans or anybody else might be right or wrong, but they usually have nothing to do with the argument at hand. An idea can't be responsible for who supports it or opposes it. The idea must stand or fall on its own merits.
(Note: "Usually." A personal attack is more often than not irrelevant, which qualifies it as an ad hominem fault. But on rare occasions, as any good lawyer can tell you, it is valid to attack a person in order to cast doubt on the person's views. If Mr. Smith argues that a certain plot of land is absolutely the only place the new civic center can possibly be constructed, it is of more than passing interest if Mr. Smith has just purchased that plot. Sometimes the person is the issue.)
2. Argumentum Ad Populum (appeal to the masses)
A variation on the ad hominem argument. This appeals to our desire to be like everybody else, to herd, not go against the grain. Ninety percent of the population agreed to such-and-such a proposition, so it must be right. Well, no, it musn't. An idea can be good if nobody supports it, bad if everybody does. A great deal of advertising dollars are spent making ad populum appeals. You don't want to be left out of the in-group, do you? Better buy this or try that. It's a lousy tactic for advertising, worse for editorial pages. A couple of variations on this variation are the appeal to common practice ("Golly, officer, everybody else was doing 70 m.p.h. I was just trying to keep up") and the appeal to past practice ("But it's always been done this way"). "Past practice" shows up on editorial pages quite frequently, sometimes disguised as "Things sure are different today" or "We didn't do it that way in my day." Maybe so, but irrelevant to the worthiness or unworthiness of something.
3. Argumentum Ad Verecundiam (appeal to authority)
Another ad hominem variation. This idea must be right because the president or the pope or the mayor is for it. These kinds of people must know what they're talking about, so how can we be against what they're for? Well, because they might be wrong, that's why. An idea, remember, must stand or fall on its own merits, regardless of who is for or against it, and you must still make a valid argument for it. (Again, such appeals are usually irrelevant, but common sense tells us we must sometimes defer to authority. If your own examination tells you that you are as fit as a fiddle, but the doctor says you need tests right away, go with the doctor's opinion.) Parents, it should be noted, were probably the first people ever to use the ad verecundiam argument: "Why? Because I said so, that's why!"
4. Post Hoc, Ergo Propter Hoc (after this, therefore because of this)
Sometimes called "post hoc reasoning" or the "post hoc fallacy." The assumption that, because one event follows another, the first event must have caused the second event. Things that happen in sequence might be related, or it might just be coincidence. Sequence doesn't prove an argument. A common post hoc argument in the late '60s was: "More than half the people who use hard drugs stared out by smoking marijuana. Therefore, use of marijuana leads to use of hard drugs." The critics answered: "But 90 percent of the people who use hard drugs chewed gum as a child. Therefore, chewing gum leads to the use of hard drugs."
Because informal logic makes generalizations based on the observation of specifics, it is extremely susceptible to the post-hoc fallacy. Common sense tells us that there has to be causation in some sequences: A man points a gun and shoots -- somebody falls down and dies; one event caused the other. But we also know that in many cases the sequence of events is irrelevant: There is a full moon -- the murder rate goes up; the full moon did not cause the murder rate to increase.
The point is: Merely stating that one thing follows another does not prove an argument. With that alone, you have not made your case.
5. The Red Herring
Introducing an irrelevant point, the result of which is to divert attention from the original issue. You are arguing about abortion. Somebody compares it to the Holocaust of World War II, and suddenly you are arguing about that. With the red herring introduced, you end up attempting to argue about a conclusion that is not really the one at issue. An example: "Is the government really spending too much money, as its critics contend? If the government did not spend that money, how would the private sector use it? Would it spend it wisely, or merely waste it?" The argument then proceeds to detail all the misuses of money ever committed by the private sector. The original question ("Is the government spending too much?") is ignored or forgotten, but we think we have "proven" it by exploring the red herring.
(There are two stories about how this fallacy got its name, which may or may not be truthful. One is that escaping prisoners rubbed themselves with a herring, which turns red or brown when it spoils, to throw chasing dogs off the scent. The other is that, during English fox hunts of old, a herring was thrown in front of the dog, either to stop a dog who was being trained or to save a particularly energetic fox for the next hunt.)
6. Begging the question
Also called "arguing in a circle." When the conclusion (the statement you are supposed to "prove" to be true) is taken for granted as true and shows up as one of your premises.
An example from "The Art of Argument" by Giles St. Aubyn: "Proof of God's existence can be found in the Old Testament. The Old Testament is valid because it was divinely inspired." Another one: "It is degrading for a man to live on a dole or any payment made to him without his being required to render some service in return. The reason is that he becomes, from an economic standpoint, a parasite on the community as a whole, a position that is inconsistent with the maintenance of an individual's self-respect." In other words, it is degrading to accept unemployment pay without working for it, because to have unemployment pay without working for it is degrading.
Another example, from "Logical Self-Defense" by Ralph Johnson and J. Anthony Blair: Two medieval Jews were engaged in a dispute about the spiritual gifts of their respective rabbis. To clinch his case, one of them said, "I'll give you proof positive that my rabbi is the most gifted in the world. Is there another rabbi who dances with angels every night after he falls asleep?" His friend was skeptical. "How do you know that your rabbi really does dance every night with the angels?" he demanded. "Why," replied the first, "because he told me so himself!" The skeptic insisted: "But can you believe him?" "What!" exclaimed the first angrily. "Would a rabbi who dances with the angels each night lie?"
In begging the question, or the "arguing in a circle" fallacy, we are expected to accept as true something that we should ask to be proven as true. If you want to know this might be happening, listen or look for certain code phrases: It is beyond argument that ... It is without question that ... There is no dispute that ... It is commonly accepted that ... It cannot be denied that ... It is evident that ... It stands to reason that ... Everybody knows that ... If you hear or read one of those expressions, clear your throat and throw a wrench into the argument: "Uh, excuse me, what's your proof of that?"
7. Straw man
Misrepresenting the position of your opponent or an argument for the other side, then arguing against the misrepresentation. Generally, the "straw man" fallacy exaggerates the opposing argument, makes it so outrageous that it's easy to demolish. A perfectly logical case will then be made, but a case that has absolutely nothing to do with the question in dispute. I say, "The penalties for marijuana use are much too harsh." You respond, "He wants to end all drug laws. That would keep a lot of dangerous drug dealers on the loose. Would that be good for America?" You have demolished an argument I never made and so are guilty of the straw-man sin. If you say, "American cars are just too expensive these days," and I reply, "It is irresponsible of you to encourage the buying of Japanese cars -- it's going to destroy all of our jobs," I am guilty of the same sin.
8. Slippery slope
This is a sort of "post-hoc" argument but based on events that might happen in the future instead of events that have already happened. Every time you hear dire warnings about what might result in the future if we do this thing or don't do that thing, you're hearing a slippery-slope argument. If we approve GATT, this will happen and that will happen, and before you know it all our jobs will move to Asia and Mexico. If we don't teach sex education in schools, this will happen and that will happen, and before long teen pregnancy and sexually transmitted diseases will double.
As with the post-hoc fallacy, the problem with slippery slope is one of causation. An event that happens after another event might be caused by the first event, but then again it might not be. And slippery slope is even more dangerous (less likely to be valid) than a post-hoc argument. At least in post-hoc, we know the events have taken place; we merely have to establish causation. With slippery slope, we not only have to establish causation but predict the occurrence of the events as well.
One of the most famous slippery-slope arguments of the recent past was the "domino theory" of Communist aggression during the Vietnam War. Communism had to be stopped in Vietnam, it was argued, or every other nation in the region would topple to Communism, just like dominoes in a row. To this day, you can hear one group of people argue that the domino theory was nonsense and another group that argues just as vehemently that it was exactly right.
9. The Sweeping Generalization
This occurs, points out S. Morris Engel in "With Good Reason," when "a general rule is applied to a specific case to which the rule is not applicable because of special features of the case." He gives two good examples: "Everyone has a right to his own property. Therefore, even though Jones has been declared insane, you had no right to take away his weapon." The first premise is commonly accepted, but it is not meant to apply in all cases, especially when a person has been declared insane and the property in question is a gun. "Since horseback riding is a healthful exercise, Harry Brown ought to do more of it because it will be good for his heart condition." What is good for someone in normal health does not apply when special health problems exist.
10. The Hasty Conclusion
The reverse of the sweeping generalization. Your premises might be relevant, but they are not enough to support the conclusion. This is especially true if you are relying on anecdotal evidence or use just one occurrence of an event, particularly if it is isolated or a personal observation, to make sweeping statements. "My father drank too much. All men are drunken swine." Hasty. "My girlfriend ran a stop sign. Guess that just proves women are lousy drivers." Very hasty.
11. Bifurcation
(From the Latin prefix "bi," meaning "two," and "furka," meaning "fork" or "branch.") Using an either/or statement (or an implied either/or statement) to argue that there are only two possibilities when in fact there might be many more alternatives. "Love it or leave it" used to be a shouted slogan about America in the 1960s. Two options expressed as mutually exclusive choices. You had to do one or the other; there were no other possibilities. Well, yes, there were, said critics. How about "Love it and try to change it for the better"? Some things truly are either/or -- you can only be one or the other. You can be alive or dead. Man or woman. Rich or poor. But usually things are not so clear-cut. The statement "We must either pass the new federal budget or watch this nation go down the drain" ignores a whole range of other possibilities. Such as a new version of the budget, or a new budget altogether. Or state action that might substitute for missing federal funds. Or action from the private sector. And on and on.
12. Faulty Analogy
An analogy is a comparison between two like things or situations. It can be one of the most useful rhetorical tools at the disposal of an opinion writer. Comparing one thing to something else can help bring it into sharper focus, make it clearer to more people. If you want to argue about the legalization of drugs, either for or against, you might have trouble because our nation has had no recent experience with it (so you might end up on that old Slippery Slope). But you can make an analogy to the prohibition of alcohol, which our nation has experienced. If you want to argue for the legalization of drugs, you can point out that the prohibition of alcohol created a whole new class of criminals and increased the violence in this country, and that the illegality of drugs has had the same effect. If you want to argue against the legalization of drugs, you can point out that Prohibition resulted in a drop in the excessive use of alcohol in this nation, which improved our health overall, and that the illegality of drugs has the same beneficial effect. Both analogies would be apt, and you would have used them to make a valid point.
During the Persian Gulf war, numerous analogies were made comparing the war to the one in Vietnam. One writer said Vietnam proved the American people wouldn't stand for a long, unpopular war, so we had to make this war short. Another said Vietnam proved you can't wage a war without a clearly defined purpose, so the Persian Gulf generals had better have a specific mission: Get back Kuwait, nothing else. Some of the Vietnam analogies were valid, some less so. If you examine the two wars, you discover some differences. One in the jungle, one in the desert. One over an abstract -- "fighting for democracy." One over something very concrete -- oil. A nation divided over one, a nation strongly for the other. Different missions, tactics, goals, times.
A faulty analogy occurs when the two things being compared really aren't as similar as they appear to be. Many who oppose abortion compare it to the Holocaust during World War II when millions of Jews were killed in Nazi Germany. That makes a striking and memorable analogy, but the two situations are too different for the analogy to be valid. In the Holocaust, for example, basic human rights were denied the many by the actions of a powerful few. Whatever else abortion is, it usually involves a decision by one person. There are many powerful and compelling arguments for and against abortion. Using a faulty analogy merely diverts attention from those valid arguments. In the early days of the women's liberation movement, many comparisons were made to the black civil-rights struggle. There were some valid comparisons, but you wouldn't want to push the analogy too far. Different treatment of two groups because of skin color isn't exactly like different treatment because of sex differences. For example, you might not want to use the valid argument against separate restroom facilities for blacks and whites when it comes to men and women.
13. Argumentum Ad Ignorantiam (appeal to ignorance)
Trying to win an argument merely by claiming that it has never been disproven: President Kennedy must have been killed as a result of a conspiracy, because no one has been able to show it was not a conspiracy. Elvis must be alive and well, and an impostor buried in his place, because no one has dug up the body to prove otherwise. You will be making an emotional appeal, and putting the other side on the defensive, but you won't have proven anything.
14. Argumentum Ad Baculum (appeal to force)
If we don't do this, someone will make us do it. Maybe they will, maybe they wont, but the mere fact that they might doesn't add to the validity of the argument you're trying to make.
15. Argumentum Ad Absurdum (arguing the absurd extreme)
Trying to prove or disprove an argument by projecting the consequences as far as you possibly can -- this is "slippery slope" gone wildly out of control. As in: "I really should buy a lottery ticket. I might win that $15,000 prize. Then I can buy that hot car I've been looking at. Then old Greely will see me driving and realize I'm a winner and give me that promotion he's been stalling on. Then Linda will finally notice me, and we'll get married and work hard and live happily ever after and ... Oops. I just remembered that the odds on the lottery are a zillion to one."
16. The Tu Quoque Fallacy ("you're another")
Accusing the accuser of the same charge. This is the "So's your old man" kind of thing we used to hear in the schoolyard. In "Fundamentals of Logic," this example is given: "So these are your grounds for criticizing the way we treat our native population? In answer let me say, 'Who was it that killed most of the American Indians?' " Notice that no answering argument has been offered to the charge that the native population is treated badly. Instead we are diverted to a totally irrelevant consideration.
17. The Fallacy of Special Pleading
Again from "Fundamentals of Logic":
"Those who fail to mention evidence unfavorable to their claim in a situation in which all evidence is presumably being mentioned are guilty of the fallacy of special pleading. There are at least two sides to most important issues. To avoid a fallacious sort of arguing, one should consider both sides of the issue and try to show that a stronger case can be made for the side one favors.
"After the oil embargo in 1974 Congress passed a national 55 m.p.h. speed limit. There are arguments for and against this speed limit. Consider the following argument against the 'double nickel' speed limit:
We should repeal the 55 m.p.h. speed limit because of the distances that need to be traveled in the West, because of the money lost by time consumed on the part of long-haul truckers and bus companies and because no one is driving 55 m.p.h. anyhow. The double nickel law echoes the unworkable prohibition of alcohol in the '30s.
"The argument does consider some of the relevant reasons for the repeal of the 55 m.p.h. speed limit. What the argument fails to take into account are the reasons for the speed limit. The most prominent reasons are that the speed limit saves lives and saves oil. (It saves about 10,000 lives a year.) Thus the argument above is an instance of the fallacy of special pleading. To avoid the fallacy one would have to consider reasons both for and against the repeal of the national speed limit and, if possible, try to show that the stronger case can be made for repeal of the 55 m.p.h. national speed limit."
(Note: You should have spotted at least two other faults in the argument for repeal -- the appeal to common practice ("no one is driving 55 m.p.h. anyhow") and a faulty analogy (the law "echoes the unworkable prohibition against alcohol"). And one of the "facts" in the anti-repeal argument could be attacked on the grounds of accuracy. Whether the 55 m.p.h.-limit in fact "saved 10,000 lives a year" has been a matter of much dispute.)
18. The Fallacy of Equivocation
This fallacy is committed when a word or phrase is used more than once in an argument and is used in different ways. The reader expects the word to have the same meaning every time, so the result is ambiguity and confusion. Consider the following example, cited in more than one book of logic: "Only man is rational. No woman is a man. Therefore no woman is rational." If "man" were used the same way both times -- as the opposite of "woman" -- the argument would be perfectly valid. But it is not. In the "Only man is rational" statement, "man" is used in the generic sense to mean all humankind -- of all the animals, only the animals who are people are rational. In the "No woman is a man" statement, "man" is used more specifically to mean "the opposite of a woman."
Equivocation is possible whenever there is a word or phrase that can have more than one meaning. That includes a lot of words. If you try to equate the "miracles" in the Bible with the "miracles" of modern science, you are talking about two different things. And "equal" means two different things in the following sentence: "The Constitution promises that we will be equal under the law, but John and I did not get equal treatment -- he was let off with a warning, and the cop gave me a ticket." In the first occurrence, "equal" means the same right to get a fair hearing; in the latter, it means "the same results." And consider the use of "minority" today, meaning merely those groups of people whose numbers are smaller, compared to "minority" in the constitutional sense -- those whose political beliefs need protection against a tyrannical majority.
19. The Fallacy of Division
Arguing that something that is true only of the whole must also be true of the parts taken separately. "The News-Sentinel is a good newspaper. John works there. Therefore John must be a good reporter." Or: "Congress is unable to spend money wisely. Mark is a member of Congress. So Mark probably can't balance his checkbook."
20. The Fallacy of Composition
The opposite of the fallacy of division, the incorrect assumption that what is true only of the parts is also true of the whole. John and Brenda and Betty and Sam might be great writers. That does not mean if you put them all together you will have a great newspaper. The fact that you have 10 ingredients that taste good to you and combine them together does not ensure that you will end up with a food you will enjoy eating.
21. The Fallacy of Accent
This occurs when a statement is accented in a way that changes its meaning. If I write (to cite an earlier example) "The Constitution says we are all equal under the law," that is a straightforward statement about an important American principle. If I write it this way -- "The Constitution says we are all equal under the law" -- I am saying something different, that I don't believe what it says for a minute. And if I write it this way --"The Constitution says we are all equal under the law" -- I am saying yet a different thing: Maybe we are equal under the law but not in other ways. Know what you mean to say and write it that way.
22. The Fallacy of Quoting out of Context
This is a relative of the fallacy of accent, and means simply that a phrase or sentence is used without either the words or sentences before it or after it (or both) in such a way as to change the meaning of what the person speaking said. Anyone who reads newspapers can think of examples of this, and many people who have been quoted in newspaper stories can talk to you for hours about it. An example from "Fundamentals of Logic" makes the point well: "The movie critic wrote, 'The movie is flawless except for bad acting, a bad plot and bad photography.' A dishonest promoter takes out an ad for the film and employs that opinion this way: 'The movie critic wrote that "The movie is flawless ..." and that is a good reason for seeing the film.' "
Just thought I might post this so you don't enter the next stoush with your pants down. Or the spectators might enjoy spotting the common mistakes
Enjoy
Following are some of the most common logic faults. Whenever appropriate, both the common name and the Latin terminology are used:
1. Argumentum Ad Hominem (argument against the person)
This is the personal attack, probably the No. 1 logic fault you will find in opinion pieces everywhere. The ad hominem argument ignores the issue altogether and tries to discredit the person holding the idea. You once were able to discredit almost any idea by saying it was a "communistic idea." And in the political debates of today you can hear similar tactics. Liberal friends of President Clinton said he was wrong to push for the North American Free Trade Agreement and the General Agreement on Tariffs and Trade because so many Republicans were for it and they couldn't be right. And some conservatives berated the Republican support for NAFTA and GATT because "everybody knows" whatever Clinton is for must be wrong. There are a great many people these days who are against whatever Rush Limbaugh is for, for anything Richard Gephardt is against. Our views of Democrats or Republicans or anybody else might be right or wrong, but they usually have nothing to do with the argument at hand. An idea can't be responsible for who supports it or opposes it. The idea must stand or fall on its own merits.
(Note: "Usually." A personal attack is more often than not irrelevant, which qualifies it as an ad hominem fault. But on rare occasions, as any good lawyer can tell you, it is valid to attack a person in order to cast doubt on the person's views. If Mr. Smith argues that a certain plot of land is absolutely the only place the new civic center can possibly be constructed, it is of more than passing interest if Mr. Smith has just purchased that plot. Sometimes the person is the issue.)
2. Argumentum Ad Populum (appeal to the masses)
A variation on the ad hominem argument. This appeals to our desire to be like everybody else, to herd, not go against the grain. Ninety percent of the population agreed to such-and-such a proposition, so it must be right. Well, no, it musn't. An idea can be good if nobody supports it, bad if everybody does. A great deal of advertising dollars are spent making ad populum appeals. You don't want to be left out of the in-group, do you? Better buy this or try that. It's a lousy tactic for advertising, worse for editorial pages. A couple of variations on this variation are the appeal to common practice ("Golly, officer, everybody else was doing 70 m.p.h. I was just trying to keep up") and the appeal to past practice ("But it's always been done this way"). "Past practice" shows up on editorial pages quite frequently, sometimes disguised as "Things sure are different today" or "We didn't do it that way in my day." Maybe so, but irrelevant to the worthiness or unworthiness of something.
3. Argumentum Ad Verecundiam (appeal to authority)
Another ad hominem variation. This idea must be right because the president or the pope or the mayor is for it. These kinds of people must know what they're talking about, so how can we be against what they're for? Well, because they might be wrong, that's why. An idea, remember, must stand or fall on its own merits, regardless of who is for or against it, and you must still make a valid argument for it. (Again, such appeals are usually irrelevant, but common sense tells us we must sometimes defer to authority. If your own examination tells you that you are as fit as a fiddle, but the doctor says you need tests right away, go with the doctor's opinion.) Parents, it should be noted, were probably the first people ever to use the ad verecundiam argument: "Why? Because I said so, that's why!"
4. Post Hoc, Ergo Propter Hoc (after this, therefore because of this)
Sometimes called "post hoc reasoning" or the "post hoc fallacy." The assumption that, because one event follows another, the first event must have caused the second event. Things that happen in sequence might be related, or it might just be coincidence. Sequence doesn't prove an argument. A common post hoc argument in the late '60s was: "More than half the people who use hard drugs stared out by smoking marijuana. Therefore, use of marijuana leads to use of hard drugs." The critics answered: "But 90 percent of the people who use hard drugs chewed gum as a child. Therefore, chewing gum leads to the use of hard drugs."
Because informal logic makes generalizations based on the observation of specifics, it is extremely susceptible to the post-hoc fallacy. Common sense tells us that there has to be causation in some sequences: A man points a gun and shoots -- somebody falls down and dies; one event caused the other. But we also know that in many cases the sequence of events is irrelevant: There is a full moon -- the murder rate goes up; the full moon did not cause the murder rate to increase.
The point is: Merely stating that one thing follows another does not prove an argument. With that alone, you have not made your case.
5. The Red Herring
Introducing an irrelevant point, the result of which is to divert attention from the original issue. You are arguing about abortion. Somebody compares it to the Holocaust of World War II, and suddenly you are arguing about that. With the red herring introduced, you end up attempting to argue about a conclusion that is not really the one at issue. An example: "Is the government really spending too much money, as its critics contend? If the government did not spend that money, how would the private sector use it? Would it spend it wisely, or merely waste it?" The argument then proceeds to detail all the misuses of money ever committed by the private sector. The original question ("Is the government spending too much?") is ignored or forgotten, but we think we have "proven" it by exploring the red herring.
(There are two stories about how this fallacy got its name, which may or may not be truthful. One is that escaping prisoners rubbed themselves with a herring, which turns red or brown when it spoils, to throw chasing dogs off the scent. The other is that, during English fox hunts of old, a herring was thrown in front of the dog, either to stop a dog who was being trained or to save a particularly energetic fox for the next hunt.)
6. Begging the question
Also called "arguing in a circle." When the conclusion (the statement you are supposed to "prove" to be true) is taken for granted as true and shows up as one of your premises.
An example from "The Art of Argument" by Giles St. Aubyn: "Proof of God's existence can be found in the Old Testament. The Old Testament is valid because it was divinely inspired." Another one: "It is degrading for a man to live on a dole or any payment made to him without his being required to render some service in return. The reason is that he becomes, from an economic standpoint, a parasite on the community as a whole, a position that is inconsistent with the maintenance of an individual's self-respect." In other words, it is degrading to accept unemployment pay without working for it, because to have unemployment pay without working for it is degrading.
Another example, from "Logical Self-Defense" by Ralph Johnson and J. Anthony Blair: Two medieval Jews were engaged in a dispute about the spiritual gifts of their respective rabbis. To clinch his case, one of them said, "I'll give you proof positive that my rabbi is the most gifted in the world. Is there another rabbi who dances with angels every night after he falls asleep?" His friend was skeptical. "How do you know that your rabbi really does dance every night with the angels?" he demanded. "Why," replied the first, "because he told me so himself!" The skeptic insisted: "But can you believe him?" "What!" exclaimed the first angrily. "Would a rabbi who dances with the angels each night lie?"
In begging the question, or the "arguing in a circle" fallacy, we are expected to accept as true something that we should ask to be proven as true. If you want to know this might be happening, listen or look for certain code phrases: It is beyond argument that ... It is without question that ... There is no dispute that ... It is commonly accepted that ... It cannot be denied that ... It is evident that ... It stands to reason that ... Everybody knows that ... If you hear or read one of those expressions, clear your throat and throw a wrench into the argument: "Uh, excuse me, what's your proof of that?"
7. Straw man
Misrepresenting the position of your opponent or an argument for the other side, then arguing against the misrepresentation. Generally, the "straw man" fallacy exaggerates the opposing argument, makes it so outrageous that it's easy to demolish. A perfectly logical case will then be made, but a case that has absolutely nothing to do with the question in dispute. I say, "The penalties for marijuana use are much too harsh." You respond, "He wants to end all drug laws. That would keep a lot of dangerous drug dealers on the loose. Would that be good for America?" You have demolished an argument I never made and so are guilty of the straw-man sin. If you say, "American cars are just too expensive these days," and I reply, "It is irresponsible of you to encourage the buying of Japanese cars -- it's going to destroy all of our jobs," I am guilty of the same sin.
8. Slippery slope
This is a sort of "post-hoc" argument but based on events that might happen in the future instead of events that have already happened. Every time you hear dire warnings about what might result in the future if we do this thing or don't do that thing, you're hearing a slippery-slope argument. If we approve GATT, this will happen and that will happen, and before you know it all our jobs will move to Asia and Mexico. If we don't teach sex education in schools, this will happen and that will happen, and before long teen pregnancy and sexually transmitted diseases will double.
As with the post-hoc fallacy, the problem with slippery slope is one of causation. An event that happens after another event might be caused by the first event, but then again it might not be. And slippery slope is even more dangerous (less likely to be valid) than a post-hoc argument. At least in post-hoc, we know the events have taken place; we merely have to establish causation. With slippery slope, we not only have to establish causation but predict the occurrence of the events as well.
One of the most famous slippery-slope arguments of the recent past was the "domino theory" of Communist aggression during the Vietnam War. Communism had to be stopped in Vietnam, it was argued, or every other nation in the region would topple to Communism, just like dominoes in a row. To this day, you can hear one group of people argue that the domino theory was nonsense and another group that argues just as vehemently that it was exactly right.
9. The Sweeping Generalization
This occurs, points out S. Morris Engel in "With Good Reason," when "a general rule is applied to a specific case to which the rule is not applicable because of special features of the case." He gives two good examples: "Everyone has a right to his own property. Therefore, even though Jones has been declared insane, you had no right to take away his weapon." The first premise is commonly accepted, but it is not meant to apply in all cases, especially when a person has been declared insane and the property in question is a gun. "Since horseback riding is a healthful exercise, Harry Brown ought to do more of it because it will be good for his heart condition." What is good for someone in normal health does not apply when special health problems exist.
10. The Hasty Conclusion
The reverse of the sweeping generalization. Your premises might be relevant, but they are not enough to support the conclusion. This is especially true if you are relying on anecdotal evidence or use just one occurrence of an event, particularly if it is isolated or a personal observation, to make sweeping statements. "My father drank too much. All men are drunken swine." Hasty. "My girlfriend ran a stop sign. Guess that just proves women are lousy drivers." Very hasty.
11. Bifurcation
(From the Latin prefix "bi," meaning "two," and "furka," meaning "fork" or "branch.") Using an either/or statement (or an implied either/or statement) to argue that there are only two possibilities when in fact there might be many more alternatives. "Love it or leave it" used to be a shouted slogan about America in the 1960s. Two options expressed as mutually exclusive choices. You had to do one or the other; there were no other possibilities. Well, yes, there were, said critics. How about "Love it and try to change it for the better"? Some things truly are either/or -- you can only be one or the other. You can be alive or dead. Man or woman. Rich or poor. But usually things are not so clear-cut. The statement "We must either pass the new federal budget or watch this nation go down the drain" ignores a whole range of other possibilities. Such as a new version of the budget, or a new budget altogether. Or state action that might substitute for missing federal funds. Or action from the private sector. And on and on.
12. Faulty Analogy
An analogy is a comparison between two like things or situations. It can be one of the most useful rhetorical tools at the disposal of an opinion writer. Comparing one thing to something else can help bring it into sharper focus, make it clearer to more people. If you want to argue about the legalization of drugs, either for or against, you might have trouble because our nation has had no recent experience with it (so you might end up on that old Slippery Slope). But you can make an analogy to the prohibition of alcohol, which our nation has experienced. If you want to argue for the legalization of drugs, you can point out that the prohibition of alcohol created a whole new class of criminals and increased the violence in this country, and that the illegality of drugs has had the same effect. If you want to argue against the legalization of drugs, you can point out that Prohibition resulted in a drop in the excessive use of alcohol in this nation, which improved our health overall, and that the illegality of drugs has the same beneficial effect. Both analogies would be apt, and you would have used them to make a valid point.
During the Persian Gulf war, numerous analogies were made comparing the war to the one in Vietnam. One writer said Vietnam proved the American people wouldn't stand for a long, unpopular war, so we had to make this war short. Another said Vietnam proved you can't wage a war without a clearly defined purpose, so the Persian Gulf generals had better have a specific mission: Get back Kuwait, nothing else. Some of the Vietnam analogies were valid, some less so. If you examine the two wars, you discover some differences. One in the jungle, one in the desert. One over an abstract -- "fighting for democracy." One over something very concrete -- oil. A nation divided over one, a nation strongly for the other. Different missions, tactics, goals, times.
A faulty analogy occurs when the two things being compared really aren't as similar as they appear to be. Many who oppose abortion compare it to the Holocaust during World War II when millions of Jews were killed in Nazi Germany. That makes a striking and memorable analogy, but the two situations are too different for the analogy to be valid. In the Holocaust, for example, basic human rights were denied the many by the actions of a powerful few. Whatever else abortion is, it usually involves a decision by one person. There are many powerful and compelling arguments for and against abortion. Using a faulty analogy merely diverts attention from those valid arguments. In the early days of the women's liberation movement, many comparisons were made to the black civil-rights struggle. There were some valid comparisons, but you wouldn't want to push the analogy too far. Different treatment of two groups because of skin color isn't exactly like different treatment because of sex differences. For example, you might not want to use the valid argument against separate restroom facilities for blacks and whites when it comes to men and women.
13. Argumentum Ad Ignorantiam (appeal to ignorance)
Trying to win an argument merely by claiming that it has never been disproven: President Kennedy must have been killed as a result of a conspiracy, because no one has been able to show it was not a conspiracy. Elvis must be alive and well, and an impostor buried in his place, because no one has dug up the body to prove otherwise. You will be making an emotional appeal, and putting the other side on the defensive, but you won't have proven anything.
14. Argumentum Ad Baculum (appeal to force)
If we don't do this, someone will make us do it. Maybe they will, maybe they wont, but the mere fact that they might doesn't add to the validity of the argument you're trying to make.
15. Argumentum Ad Absurdum (arguing the absurd extreme)
Trying to prove or disprove an argument by projecting the consequences as far as you possibly can -- this is "slippery slope" gone wildly out of control. As in: "I really should buy a lottery ticket. I might win that $15,000 prize. Then I can buy that hot car I've been looking at. Then old Greely will see me driving and realize I'm a winner and give me that promotion he's been stalling on. Then Linda will finally notice me, and we'll get married and work hard and live happily ever after and ... Oops. I just remembered that the odds on the lottery are a zillion to one."
16. The Tu Quoque Fallacy ("you're another")
Accusing the accuser of the same charge. This is the "So's your old man" kind of thing we used to hear in the schoolyard. In "Fundamentals of Logic," this example is given: "So these are your grounds for criticizing the way we treat our native population? In answer let me say, 'Who was it that killed most of the American Indians?' " Notice that no answering argument has been offered to the charge that the native population is treated badly. Instead we are diverted to a totally irrelevant consideration.
17. The Fallacy of Special Pleading
Again from "Fundamentals of Logic":
"Those who fail to mention evidence unfavorable to their claim in a situation in which all evidence is presumably being mentioned are guilty of the fallacy of special pleading. There are at least two sides to most important issues. To avoid a fallacious sort of arguing, one should consider both sides of the issue and try to show that a stronger case can be made for the side one favors.
"After the oil embargo in 1974 Congress passed a national 55 m.p.h. speed limit. There are arguments for and against this speed limit. Consider the following argument against the 'double nickel' speed limit:
We should repeal the 55 m.p.h. speed limit because of the distances that need to be traveled in the West, because of the money lost by time consumed on the part of long-haul truckers and bus companies and because no one is driving 55 m.p.h. anyhow. The double nickel law echoes the unworkable prohibition of alcohol in the '30s.
"The argument does consider some of the relevant reasons for the repeal of the 55 m.p.h. speed limit. What the argument fails to take into account are the reasons for the speed limit. The most prominent reasons are that the speed limit saves lives and saves oil. (It saves about 10,000 lives a year.) Thus the argument above is an instance of the fallacy of special pleading. To avoid the fallacy one would have to consider reasons both for and against the repeal of the national speed limit and, if possible, try to show that the stronger case can be made for repeal of the 55 m.p.h. national speed limit."
(Note: You should have spotted at least two other faults in the argument for repeal -- the appeal to common practice ("no one is driving 55 m.p.h. anyhow") and a faulty analogy (the law "echoes the unworkable prohibition against alcohol"). And one of the "facts" in the anti-repeal argument could be attacked on the grounds of accuracy. Whether the 55 m.p.h.-limit in fact "saved 10,000 lives a year" has been a matter of much dispute.)
18. The Fallacy of Equivocation
This fallacy is committed when a word or phrase is used more than once in an argument and is used in different ways. The reader expects the word to have the same meaning every time, so the result is ambiguity and confusion. Consider the following example, cited in more than one book of logic: "Only man is rational. No woman is a man. Therefore no woman is rational." If "man" were used the same way both times -- as the opposite of "woman" -- the argument would be perfectly valid. But it is not. In the "Only man is rational" statement, "man" is used in the generic sense to mean all humankind -- of all the animals, only the animals who are people are rational. In the "No woman is a man" statement, "man" is used more specifically to mean "the opposite of a woman."
Equivocation is possible whenever there is a word or phrase that can have more than one meaning. That includes a lot of words. If you try to equate the "miracles" in the Bible with the "miracles" of modern science, you are talking about two different things. And "equal" means two different things in the following sentence: "The Constitution promises that we will be equal under the law, but John and I did not get equal treatment -- he was let off with a warning, and the cop gave me a ticket." In the first occurrence, "equal" means the same right to get a fair hearing; in the latter, it means "the same results." And consider the use of "minority" today, meaning merely those groups of people whose numbers are smaller, compared to "minority" in the constitutional sense -- those whose political beliefs need protection against a tyrannical majority.
19. The Fallacy of Division
Arguing that something that is true only of the whole must also be true of the parts taken separately. "The News-Sentinel is a good newspaper. John works there. Therefore John must be a good reporter." Or: "Congress is unable to spend money wisely. Mark is a member of Congress. So Mark probably can't balance his checkbook."
20. The Fallacy of Composition
The opposite of the fallacy of division, the incorrect assumption that what is true only of the parts is also true of the whole. John and Brenda and Betty and Sam might be great writers. That does not mean if you put them all together you will have a great newspaper. The fact that you have 10 ingredients that taste good to you and combine them together does not ensure that you will end up with a food you will enjoy eating.
21. The Fallacy of Accent
This occurs when a statement is accented in a way that changes its meaning. If I write (to cite an earlier example) "The Constitution says we are all equal under the law," that is a straightforward statement about an important American principle. If I write it this way -- "The Constitution says we are all equal under the law" -- I am saying something different, that I don't believe what it says for a minute. And if I write it this way --"The Constitution says we are all equal under the law" -- I am saying yet a different thing: Maybe we are equal under the law but not in other ways. Know what you mean to say and write it that way.
22. The Fallacy of Quoting out of Context
This is a relative of the fallacy of accent, and means simply that a phrase or sentence is used without either the words or sentences before it or after it (or both) in such a way as to change the meaning of what the person speaking said. Anyone who reads newspapers can think of examples of this, and many people who have been quoted in newspaper stories can talk to you for hours about it. An example from "Fundamentals of Logic" makes the point well: "The movie critic wrote, 'The movie is flawless except for bad acting, a bad plot and bad photography.' A dishonest promoter takes out an ad for the film and employs that opinion this way: 'The movie critic wrote that "The movie is flawless ..." and that is a good reason for seeing the film.' "