Excerpt from An Illustrated Book of Bad Arguments by Ali Almossawi
Argument from Consequences
Arguing from consequences is speaking for or against the truth of a statement by appealing to the consequences it would have if true (or if false). But the fact that a proposition leads to some unfavorable result does not mean that it is false. Similarly, just because a proposition has good consequences does not all of a sudden make it true. As history professor and author David Hackett Fischer puts it, “It does not follow that a quality which attaches to an effect is transferable to the cause” [Fischer].
In the case of good consequences, such an argument may appeal to an audience’s hopes, which at times take the form of wishful thinking. In the case of bad consequences, the argument may instead play on an audience’s fears. For example, take Dostoevsky’s line, “If God does not exist, then everything is permitted.” Discussions of objective morality aside, the apparent grim consequences of a purely materialistic world say nothing about whether or not it is true that God exists.
One should keep in mind that such arguments are faulty only when they are used to support or deny the truth of a statement, and not when they deal with decisions or policies [Curtis]. For example, a politician may logically oppose raising taxes for fear that it would adversely impact the lives of his constituents.
This fallacy is one of many in this book that can be termed a red herring, because it subtly redirects the discussion away from the original proposition—in this case, to the proposition’s result.
To “put up a straw man” is to intentionally caricature a person’s argument with the aim of attacking the caricature rather than the actual argument. Misrepresenting, misquoting, misconstruing, and oversimplifying an opponent’s position are all means by which one can commit this fallacy. The straw man argument is usually more absurd than the actual argument, making it an easier target to attack. It may also lure the other person toward defending the more ridiculous argument rather than their original one.
For example, a skeptic of Darwinism might say, “My opponent is trying to convince you that we evolved from chimpanzees who were swinging from trees, a truly ludicrous claim.” This is a misrepresentation of what evolutionary biology actually claims, which is that humans and chimpanzees shared a common ancestor millions of years ago. Misrepresenting the idea is much easier than refuting the evidence for it.
Appeal to Irrelevant Authority
An appeal to authority is an appeal to one’s sense of modesty, which is to say, an appeal to the feeling that others are more knowledgeable [Engel], which may often—but of course not always—be true. One may reasonably appeal to pertinent authority, as scientists and academics typically do. A vast majority of the things that we believe in, such as atoms and the solar system, are on reliable authority, as are all historical statements, to paraphrase C. S. Lewis. An argument is more likely to be fallacious when the appeal is made to an irrelevant authority, one who is not an expert on the issue at hand. A similar appeal worth noting is the appeal to vague authority, where an idea is attributed to a faceless collective. For example, “Professors in Germany showed such and such to be true.”
One type of appeal to irrelevant authority is the appeal to ancient wisdom, in which a belief is assumed to be true just because it originated some time ago. For example, “Astrology was practiced in ancient China, one of the most technologically advanced civilizations of the day.” This type of appeal often overlooks the fact that some things are idiosyncratic and change naturally over time. For example, “We do not get enough sleep nowadays. Just a few centuries ago, people used to sleep for nine hours a night.” There are all sorts of reasons why people might have slept longer in the past. The fact that they did is insufficient evidence for the argument that we should do so today.
Equivocation exploits the ambiguity of language by changing the meaning of a word during the course of an argument and using the different meanings to support an ill-founded conclusion.2 (A word whose meaning is maintained throughout an argument is described as being used univocally.) Consider the following argument: “How can you be against faith when you take leaps of faith all the time: making investments, trusting friends, and even getting engaged?” Here, the meaning of the word “faith” is shifted from a spiritual belief in a creator to a willingness to undertake risks.
This fallacy is commonly invoked in discussions of science and religion, where the word “why” may be used equivocally. In one context, it is a word that seeks cause, which as it happens is the main driver of science, and in another it is a word that seeks purpose, which deals with morality and other realms where science may well have no answers. For example, one might argue: “Science cannot tell us why things are. Why do we exist? Why be moral? Thus, we need some other source to tell us why things happen.”
A false dilemma is an argument that presents a limited set of two possible categories and assumes that everything in the scope of the discussion must be an element of that set.3 Thus, by rejecting one category, you are forced to accept the other. For example, “In the war on fanaticism, there are no sidelines; you are either with us or with the fanatics.” In reality, there is a third option, one could very well be neutral; and a fourth option, one may be against both; and even a fifth option, one may empathize with elements of both.
In The Strangest Man, Paul Dirac’s biographer recounts a parable that physicist Ernest Rutherford once told his colleague Niels Bohr: A man bought a parrot from a pet store, only to bring it back because it didn’t talk. After several such visits, the store manager eventually said, “Oh, that’s right! You wanted a parrot that talks. Please forgive me. I gave you the parrot that thinks” [Farmelo]. Rutherford was clearly using the parable to illustrate the genius of the silent Dirac, but one can imagine how someone might use such a line of reasoning to suggest that a person is either silent and a thinker or talkative and an imbecile.
Not a Cause for a Cause
This fallacy assumes a cause for an event where there is no evidence that one exists.When two events occur one after the other (or simultaneously), this may be by coincidence, or due to some other unknown factor. One cannot conclude that one event caused the other without evidence. “The recent earthquake was because we disobeyed the king” is not a good argument.
This fallacy has two specific types: “after this, therefore because of this” (post hoc ergo propter hoc) and “with this, therefore because of this” (cum hoc ergo propter hoc). With the former, because one event preceded another, it is said to have been the cause. With the latter, because an event happened at the same time as another, it is said to have been the cause. In various disciplines, this is known as confusing correlation with causation.4
Here is an example paraphrased from comedian Stewart Lee: “I can’t say that, because in 1976 I did a drawing of a robot and then Star Wars came out, they must have copied the idea from me.” And here is another that I recently saw on an online forum: “The hacker took down the railway company’s website, and when I checked the train schedule, what do you know, they were all delayed!” What the poster failed to realize is that trains can be late for all kinds of reasons, so without any kind of scientific control, the inference that the hacker was the cause is unfounded.
Appeal to Fear
This fallacy plays on the fears of an audience by imagining a scary future that would be of their making if some proposition were accepted. Rather than provide solid evidence that the proposition would lead to a certain conclusion (which might be a legitimate cause for fear), such arguments rely on rhetoric, threats, or outright lies. For example, “I ask all employees to vote for my chosen candidate in the upcoming election. If the other candidate wins, he will raise taxes and many of you will lose your jobs.”
Here is another example, drawn from the novel The Trial: “You should give me all your valuables before the police get here. They will end up putting them in the storeroom, and things tend to get lost in the storeroom.” Here, although the argument is more likely a threat, albeit a subtle one, an attempt is made at reasoning. Blatant threats or orders that do not attempt to provide evidence should not be confused with this fallacy, even if they exploit one’s sense of fear [Engel].
When an appeal to fear proceeds to describe a series of terrifying events that will occur as a result of accepting a proposition—without clear causal links between them—it becomes reminiscent of a slippery slope argument. And when the person making the appeal provides one and only one alternative to the proposition under attack, it becomes reminiscent of a false dilemma.
This fallacy is committed when one forms a conclusion from a sample that is either too small or too special to be representative. For example, asking ten people on the street what they think of the president’s plan to reduce the deficit can in no way be said to gauge the sentiment of the entire nation.
Although convenient, hasty generalizations can lead to costly and catastrophic results. For instance, it may be argued that an engineering assumption led to the explosion of the Ariane 5 rocket during its first test flight: The control software had been extensively tested with the previous model, Ariane 4—but unfortunately these tests did not cover all the possible scenarios of the Ariane 5, so it was wrong to assume that the data would carry over. Signing off on such decisions typically comes down to engineers’ and managers’ ability to argue, hence the relevance of this and similar examples to our discussion of logical fallacies.
There is another example in Alice’s Adventures in Wonderland, where Alice infers that, since she is floating in a body of water, a railway station, and thus help, must be close by: “Alice had been to the seaside once in her life, and had come to the general conclusion, that wherever you go to on the English coast you find a number of bathing machines in the sea, some children digging in the sand with wooden spades, then a row of lodging houses, and behind them a railway station” [Carroll].
Appeal to Ignorance
This kind of argument assumes a proposition to be true simply because there is no evidence proving that it is false.5 Hence, absence of evidence is taken to be evidence of absence. Carl Sagan gives this example: “There is no compelling evidence that UFOs are not visiting the Earth; therefore UFOs exist” [Sagan]. Similarly, before we knew how the pyramids were built, some concluded that, unless proven otherwise, they must have been built by a supernatural power. But in fact, the “burden of proof” always lies with the person making a claim.
More logically, and as several others have put it, one should ask what is likely based on evidence from past observation. Which is more likely: That an object flying through space is a man-made artifact or natural phenomenon, or that it is aliens visiting from another planet? Since we have frequently observed the former and never the latter, it is more reasonable to conclude that UFOs are probably not aliens visiting from outer space.
A specific form of the appeal to ignorance is the argument from personal incredulity, where a person’s inability to imagine something leads them to believe that it is false. For example, “It is impossible to imagine that we actually landed a man on the moon, therefore it never happened.” Responses of this sort are sometimes wittily countered with, “That’s why you’re not a physicist!”
No True Scotsman
This argument comes up after someone has made a general claim about a group of things, and then been presented with evidence challenging that claim. Rather than revising their position, or contesting the evidence, they dodge the challenge by arbitrarily redefining the criteria for membership in that group.6
For example, someone may posit that programmers are creatures with no social skills. If someone else comes along and repudiates that claim by saying, “But John is a programmer, and he is not socially awkward at all,” this may provoke the response, “Yes, but John isn’t a true programmer.” Here, it is not clear what the attributes of a programmer are; the category is not as clearly defined as that of, say, people with blue eyes. The ambiguity allows the stubborn mind to redefine things at will.
This fallacy was coined by Antony Flew in his book Thinking about Thinking. There, he gives the following example: Hamish is reading the newspaper and comes across a story about an Englishman who has committed a heinous crime, to which he reacts by saying, “No Scotsman would do such a thing.” The next day, he comes across a story about a Scotsman who has committed an even worse crime. Instead of amending his claim about Scotsmen, he reacts by saying, “No true Scotsman would do such a thing” [Flew].
A genetic fallacy is committed when an argument is either devalued or defended solely because of its origins. In fact, an argument’s history or the origins of the person making it have no effect whatsoever on its validity. As T. Edward Damer points out, when one is emotionally attached to an idea’s origins, it is not always easy to disregard those feelings when evaluating the argument’s merit [Damer].
Consider the following argument: “Of course he supports the union workers on strike; he is, after all, from the same village.” Here, the argument supporting the workers is not being evaluated based on its merits; rather, because the person behind it happens to come from the same village as the protesters, we are led to infer that his position is worthless. Here is another example: “As men and women living in the twenty-first century, we cannot continue to hold these Bronze Age beliefs.” Why not, one might ask. Are we to dismiss all ideas that originated in the Bronze Age simply because they came about at that time?
Conversely, one may also invoke the genetic fallacy in a positive sense, by saying, for example, “Jack’s views on art cannot be contested; he comes from a long line of eminent artists.” Here, the evidence used for the inference is as lacking as in the previous examples.
Guilt by Association
Guilt by association is used to discredit an argument for proposing an idea that is shared by some socially demonized individual or group. For example, “My opponent is calling for a healthcare system that would resemble that of socialist countries. Clearly, that would be unacceptable.” Whether or not the proposed healthcare system resembles that of socialist countries has no bearing whatsoever on whether it is good or bad; it is a complete non sequitur.
Another argument, which has been repeated ad nauseam in some societies, is this: “We cannot let women drive cars because people in godless countries let their women drive cars.” Essentially, what these examples try to argue is that some group of people is absolutely and categorically bad. Hence, sharing even a single attribute with that group would make one a member of it, which would then bestow on one all the evils associated with that group.
Affirming the Consequent
One of several valid formal arguments is known as modus ponens (the mode of affirming) and takes the following form: If A then C, A; hence C. More formally: A ⇒ C, A ⊢ C. A is called the antecedent and C the consequent, and they form two premisses and a conclusion. For example:
Premiss: If A then C
If water is boiling at sea level, then its temperature is at least 100°C.
This water is boiling at sea level;
hence its temperature is at least 100°C.
Such an argument is sound in addition to being valid.
Affirming the consequent is a formal fallacy that takes this form: If A then C, C; hence A. The error lies in assuming that because the consequent is true, the antecedent must also be true, which in reality need not be the case.
For example, “People who go to college are successful. John is successful, hence he must have gone to college.” Clearly, John’s success could be a result of schooling, but it could also be a result of his upbringing, or perhaps his eagerness to overcome difficult circumstances. Generally, because schooling is not the only path to success, one cannot say that a person who is successful must have received schooling.
Appeal to Hypocrisy
Also known by its Latin name, tu quoque, meaning “you too,” this fallacy involves countering someone’s argument by pointing out that it conflicts with his or her own past actions or statements [Engel]. Thus, by answering a charge with a charge, it diverts attention from the argument at hand to the person making it. This characteristic makes the fallacy a particular type of ad hominem attack. Of course, just because someone has been inconsistent about his position does not mean that his position cannot be correct.
On an episode of the topical British TV show Have I Got News for You, a panelist objected to a protest in London against corporate greed because of the protesters’ apparent hypocrisy, pointing out that while they professed to be against capitalism, they continued to use smartphones and buy coffee.7
Here is another example, from Jason Reitman’s movie Thank You for Smoking, where a tu quoque–laden exchange is ended by the smooth-talking tobacco lobbyist Nick Naylor: “I’m just tickled by the idea of the gentleman from Vermont calling me a hypocrite when this same man, in one day, held a press conference where he called for the American tobacco fields to be slashed and burned, then he jumped on a private jet and flew down to Farm Aid where he rode a tractor onstage as he bemoaned the downfall of the American farmer.”
A slippery slope argument attempts to discredit a proposition by arguing that its acceptance will undoubtedly lead to a sequence of events, one or more of which are undesirable.8 Although the sequence of events may be possible—each transition occurring with some probability—this type of argument assumes that every transition is inevitable—while providing no evidence in support of that. This fallacy plays on the fears of an audience and is related to a number of other fallacies, such as the appeal to fear, the false dilemma, and the argument from consequences.
For example, “We shouldn’t allow people uncontrolled access to the internet. The next thing you know they will be frequenting pornographic websites, and soon enough, our entire moral fabric will disintegrate and we will be reduced to animals.” As is glaringly clear, no evidence is given, other than unfounded conjecture, that internet access implies the disintegration of a society’s moral fabric. Moreover, the argument presupposes certain things about people’s behavior within the society.
Appeal to the Bandwagon
Also known as the appeal to the people, this argument uses the fact that many people (or even a majority) believe in something as evidence that it must be true. This type of argument has often impeded the widespread acceptance of a pioneering idea. For example, most people in Galileo’s day believed that the sun and the planets orbited around Earth, so Galileo faced ridicule for his support of the Copernican model, which correctly puts the sun at the center of our solar system. More recently, physician Barry Marshall had to take the extreme measure of dosing himself with H. pylori bacteria in order to convince the scientific community that it may cause peptic ulcers, a theory that was, initially, widely dismissed.
Advertisements frequently use this method to lure people into accepting something solely because it is popular. For example, “All the cool kids use this hair gel; be one of them.” Although becoming a “cool kid” is an enticing offer, it does nothing to support the imperative that one should buy the advertised product. Politicians also use similar rhetoric to add momentum to their campaigns and influence voters.