3.3 Contributing to the Conversation
H. P. Grice proposed that there were four maxims which we assume everyone is following in a conversation. We can “flout” these rules openly, as a way of implicating something without saying it.
Someone can also abuse or exploit these rules to produce fallacious reasoning, however, by making contributions which are not known to be true, too informative or not informative enough, irrelevant, or deliberately ambiguous or vague. In general, we follow these four rules:
- Quality: make your contribution something you know to be true.
- Quantity: make your contribution as informative as needed.
- Relevance: make your contribution relevant to the conversation.
- Manner: make your contribution clear.
Table of Contents
- 3.3 Contributing to the Conversation
3.3.1 The Quality of a Contribution
Avoid “cherry picking” your evidence.
Say What you Know
Unless we’re purposefully speculating or discussing a hypothetical situation, we generally take for granted that if someone asserts something in a conversation, they take themselves to know what they said is true. In a conversation, we assume that if someone knows something relevant, they will say it, and if they don’t know something, they won’t say it. For instance, if you noticed a lot of boxes in your friend Ty’s apartment, and this made you speculate that he might be moving away, but you weren’t, you might say “Ty’s apartment looked like he might be moving” or “I think Ty might be moving” or “Maybe Ty is moving”, but you would not flatly and directly tell people “Ty away” without asking Ty first. If you said that, people would assume you had adequate evidence for it, more than just a speculation based on seeing boxes in his apartment. If you say something, people assume that you know it, and that they’re entitled to repeat what you said to others.
People sometimes violate this rule, though. Sometimes people are intentionally deceptive or insincere. Sometimes people exaggerate the truth, or pretend to know something when they are only speculating. Sometimes people repeat rumors from a source they can’t confirm, or hearsay. Sometimes people leave out that they think something is true, and simply say that it is true. Sometimes people violate the rule because their evidence is unreliable.
Cherry Picking Evidence
The most troubling violation of the rule, however, is when somebody deliberately makes it appear as though they have adequate evidence for what they say, when in reality they’ve deliberately suppressed or hidden evidence that opposes them and selected only evidence that supports them. This is called the fallacy of “cherry picking” evidence. When you buy cherries in a grocery store, what you see are only the very best of the cherries picked out from the tree: the broken, unripe, overripe, or just plain ugly cherries get turned into jam instead. Similarly, someone who “cherry picks” evidence or statistics is only showing you the information which supports their view, not the information which opposes it. For example, suppose someone says:
Dr. Magnus is incompetent. 100 people have died under his care.
At first, this may sound like a disturbing statistic about Dr. Magnus, but consider what information it leaves out. Does Dr. Magnus remove wisdom teeth, or does he treat soldiers wounded in battle? Do his patients suffer from strained tendons, or stage 4 cancer? Have those 100 people died in the 5 months since he got out of medical school, or the 50 years of a long medical practice?
Or, for example, suppose someone says:
Senator Sherwood is in the hands of corporate interests. Megacorp donated to her campaign, and she voted against a bill which would have provided money to children’s education, but for a bill which gave Megacorp a government contract.
The evidence seems conclusive against Senator Sherwood, until we realize how little we actually know. Did Megacorp donate a hundred dollars, making it a tiny percentage of contributions, or a hundred thousand dollars, making it her biggest source of funding? What else was in the bill that provided money to children’s education? Was it part of a long budget proposal with tens of thousands of different appropriations listed, or did it stand on its own? Did she later vote for the same legislation? Why did she vote for the bill which gave the contract to Megacorp? What else was in that bill? Was there any relationship between the two bills?
Consider one more example:
College students have no sense of morality nowadays. Three different polls of American Universities over the last decade have consistently found that at 80-90% of those universities there were students who admitted engaging in criminal activity within the last year.
By this point, you should be able to say what is being left out. How many polls were taken over the last decade, and were there other polls which showed different results? Were these three polls outliers? Were there polls in previous decades, and did they show different results than polls “nowadays”? More importantly, what percentage of students at least university admitted engaging in criminal activity, and how does that compare to the general population? If only 2 students at a university of 50,000 students engaged in criminal activity, that makes the student body seem better, not worse, than average. What sorts of “criminal activities” were students admitting to? Were they asked whether they had illegally downloaded music or videos, or were they asked about crimes like kidnapping and armed robbery? These are the sorts of questions that someone is expected to answer when they are accused of not saying what they know, or “cherry picking” evidence.
3.3.2 The Quantity of a Contribution
Say what you need to say, and get it over with.
Say Just What Needs to Be Said
Every time we make the choice to say something, we implicate at the same time that everything we have said needed to be said, and that nothing was left out which should have been said. For instance, imagine the following conversation:
Duane: Were any of the children hurt in the bus accident?
Chuck: The teacher survived.
Chuck implies, but doesn’t literally say, that the children did not survive, because it is assumed that Chuck would provide all of the relevant information. It would be cruel for Chuck to leave out the information that some or all of the children survived by only telling Duane that the teacher survived. On the other hand, imagine this conversation:
Duane: Were any of the children hurt in the bus accident?
Cierra: Forty children were on the bus, and their combined total mass was 207 kg, with a combined surface area of 37 square meters. Of this, 97.5% of the contiguous surface areas had no injured portions, and the remainder experienced localized inflammatory tissue responses, treated over the subsequent 24 hours with 320 mg of acetaminophen administered orally. No burials or cremations will occur.
Cierra implies, but doesn’t literally say, that all of these statistics were somehow necessary or important for fully answering Duane’s question. Duane would probably have a right to be upset with Cierra, not because she said anything false, but because what she said was far more than necessary. She could have easily said instead, “no children died, but one child had minor bruises and took some tylenol.”
Because we assume that people are saying as much and no more than necessary, certain fallacies exploit our assumptions by misleadingly providing too much information (TMI), or too little information.
TMI: Appeal to Quantity
One way to use too much information to try to mislead someone else, is to try to overwhelm them with the pure quantity or number of reasons to think something is true, rather than the strength of those reasons. For instance, someone might present a very long numbered list of reasons to believe a claim, without defending any of the particular reasons. One hundred weak reasons to think a claim is true do not necessarily overwhelm one strong reason to think the claim is false. The length of a list of reasons is an indication of the creativity of the person making the list, not of the truth of the claim.
TMI: Appeal to Length
Another way to use information to try to overwhelm one’s opponent is simply to make an argument so long that no one would reasonably have time to respond to it, or to cram so much information in a short span of time that no one could reasonably remember and follow all of it. The person who makes a very long argument will always have something left over at the end that nobody has responded to or objected to. Once again, however, hundreds of pages of weak reasons to think something is false do not necessarily outweigh a short and straightforward reason to think it is true.
TMI: Vivid Detail
A third way to try to use information to try to overwhelm one’s opponent is to use vivid descriptions to make a claim seem especially powerful, real, or persuasive, even though the details are actually irrelevant to the claim. For example, suppose that a sixth grade teacher must select one of two children to represent the school at a state spelling bee. The parent of one of the students might write:
“I entered the soft pink walls of my child’s bedroom late one night to find her fine red hair strewn across the worn, crinkled pages of her dictionary, barely visible in the moonlight; even as she dreamed, Merriam Webster laid beside her, sharing her feather pillow, and I imagined her every little snore spelling out, letter by letter, the word ‘c-h-a-m-p-i-o-n’”.
The parent’s description would not provide the teacher a legitimate reason to favor this child over the other child as a representative of the school at the spelling bee, but it might make the teacher feel as though the child is especially dedicated to spelling.
TMI: False Precision
Someone who wants to make it sound as though they have a lot of evidence on their side may make whatever statistical or numerical information they have sound more precise than it really is, since we tend to associate greater precision with more rigorous scientific investigation and thus stronger evidence. For example, instead of saying that two out of three classmates you spoke to admitted they skipped breakfast, you might say that 66.7% of your classmates skipped breakfast, making it look as though you surveyed a much larger group of classmates. You might claim that one brand of soda tastes 45% better than another brand, even though taste is very vague, to make it sound as though your confidence in the difference is stronger. You might claim that your soda has “10% more flavor”, without specifying what you are comparing your soda to.
Suppose that an opinion poll taking on Monday shows a politician’s approval rating at 45%, and an opinion poll on Friday shows their approval rating at 46%. Someone might conclude that something happened between Monday and Friday to increase the politician’s approval rating by exactly 1%. Speculating about what changed might be a serious topic of discussion on the news. This is a fallacy of false precision, however, because opinion polls tend to be accurate only within a margin of error or 3-5 percentage points anyway.
Too Little Information
Lastly, it’s worth mentioning an opposite fallacy, the use of too little information, as a means of feigning confidence or blocking questioning. For instance, suppose that somebody asks their landlord whether there has been any testing for mold in the apartment. The landlord says:
There isn’t any mold.
There is nothing irrational about the landlord’s choice to be assertive. What the landlord implicates by giving a short response, however, is that there is nothing more to be said: that the evidence that there is no mold is so overwhelming and obvious that it was silly to even bother asking the question. It would be a fallacy for the tenant to conclude from the shortness of the landlord’s response that the landlord must therefore be right.
3.3.3 The Relevance of a Contribution
There is no right time to introduce a red herring.
Relevance
When someone is making an argument, we take for granted that everything they say is something they believe to be relevant to their argument. For instance, suppose that a citizen is objecting to a plan to start controlled burns in the forest because of their unpredictable effects. The forest service agent responds:
Well, nobody can predict when lightning will strike.
The forest service agent implicates, but doesn’t say, that there is some relevant connection between the unpredictability of lightning and the need for controlled burns. What’s unspoken may be that, if there isn’t a controlled burn, the forest will be more susceptible to larger fires, including those caused by lightening, and that these fires are even more unpredictable and thus more dangerous than controlled burns.
Red Herring
One fallacy which exploits our assumption that everything said in an argument is relevant is known as the red herring. The “red herring” is information which is presented as though it were relevant, but actually sidetracks us from the issue under debate. For instance, when an issue is controversial, a “red herring” which is not controversial might be presented, even though it isn’t actually relevant:
Wanda: If we don’t increase the pay of teachers, the best teachers will quit.
Xenia: No, teachers should have professional certification before we pay them public money.
While Xenia’s claim might be something Wanda agrees with, it’s a distraction from what Wanda actually said: it is not a reason to think Wanda is wrong. On the other hand, a red herring might be a controversial claim, meant to shift the debate to some even more controversial topic:
Wanda: If we don’t increase the pay of teachers, the best teachers will quit.
Xenia: No, teachers need to stop teaching to standardized tests, it just makes our kids think like robots.
Yolanda: You’re both wrong. The problem with schools nowadays is that they are teaching sex ed instead of subtraction.
Zelda: Why do we need schools at all? Education is a sham.
We assume that there might be some relevant connection, but these red herrings actually derail the debate onto something irrelevant.
3.3.4 The Manner of a Contribution
Avoid vagueness and ambiguity, unlike this sign.
Clarity
When we are discussing complicated and controversial issues it is easy to become confused or sidetracked, and so clarity is an important virtue in conversation. Clarity means:
- Avoiding the use of obscure language, or obfuscation. For instance, someone might call torture “enhanced interrogation techniques”, or might call the sexual harassment of an employee “revealing aspects of oneself normally kept private in order to develop a closer friendship after working hours.” The ability to rephrase something in a different vocabulary does not change what it is.
- Avoiding putting information in a misleading order. For example, if someone were to say, “tomorrow I will go to work and see my mother”, this suggests he will go to work first, and then see his mother while at work, even though it doesn’t literally say that he isn’t visiting his mother on the way to work.
- Reducing the amount of unnecessary vagueness, relativity, and ambiguity in language. These things can’t be eliminated, but they can be reduced and clarified whenever there is a risk that they will potentially cause confusion.
- Ambiguity occurs when a single word or phrase has two or more meanings. For example, the term “sick” can refer to an illness, but is also has a usage in slang as a compliment meaning “great”. Similarly, to “lose” something can mean that one isn’t able to find it, or it can mean that one didn’t win the competition: if the Pirates lost the baseball game, that doesn’t mean that the Pirates couldn’t find it.
- Relativity occurs when a word or phrase depends on context or perspective for its meaning. Obvious examples are words like “right” or “left”, or “front” or “back”, which change depending on perspective. Whether 4:00am is “late at night” or an “early in the morning” depends on your sleep schedule. A child who is “tall” in comparison to kindergarten classmates is not “tall” in comparison with the teacher. What is “fast” for someone running, is not “fast’ for a car on the freeway, and that is not “fast” for a jet plane. If someone feels like they have some cold symptoms, then they might call into work and truthfully say that they are “sick”. On the other hand, when attempting to empathize with a friend who has brain cancer, it would be false for someone with cold symptoms to say, “I’m sick too.”
- Vagueness occurs when there is no clear test in “borderline cases” to determine whether or not a predicate applies to a subject. Whether an assignment is submitted “on time” or “late” is not vague: there is a clear cut-off point, the deadline, which determines whether something is “on time” or not. On the other hand, whether something is “significantly late”, “very late”, or “extremely late” is vague, because there is no clear cut-off point defined. Similarly, it is vague whether an assignment is “early” or just “on time”: an assignment turned in 50 minutes before it was due is surely not “early”, and an assignment turned in a week in advance is clearly “early”, but where is the line drawn between them?
Equivocation
The fallacy of Equivocation occurs when someone fails to eliminate ambiguity in an argument, so that the meaning of a word changes between one premise and another, or between the premises and the conclusion. For example:
1. The Congresswoman has stood up for the working class for her entire term.
2. A term in Congress lasts for two years.
3. Standing up continuously is torture.
C. The Congresswoman has endured torture for the working class for two years.
1. Philosophy is the study of the deepest stuff.
2. The deepest stuff is the stuff at the bottom of the ocean.
3. Oceanography is the study of the stuff at the bottom of the ocean.
C. Philosophy is Oceanography.
Slippery Slope
The Slippery Slope fallacy is the opposite of equivocation. It occurs when someone fails to recognize that vagueness can’t be entirely eliminated, and that we will sometimes have to make arbitrary judgments in borderline cases, but that this doesn’t mean we can’t make confident judgments in extreme cases. In other words, just because we don’t know where the cutoff point is between two things, that doesn’t mean we can’t draw a clear distinction between them. For example, we can’t draw a clear cut-off point between when someone is “barely polite” or “nearly rude”, or between when someone is “mostly healthy” or “slightly unhealthy”, or when the sky is “almost partly cloudy” or “not quite partly sunny”, but we can still recognize clear cases.
Again, we can’t draw a clear cut-off point between what kinds of life are morally significant and which kinds of life are not. Taking antibiotics clearly is not murder, and assassinating the Pope clearly is murder. People debate about where the borderline belongs. Is abortion murder? What about at 36 weeks? What about at 36 hours? Is killing a pet dog murder? How about farming animals for slaughter, or hunting for meat? What about eating fish, or shrimp, or flies, or plants? What about helping a terminally ill patient end their life early? How ill is ill enough, and how soon is too soon? We can recognize that there are tricky judgments to be made, with reasons for drawing the line at different points, without concluding that everything is murder or that nothing is murder.
Not every “Slippery Slope” argument is a fallacious argument. Because of the ways social norms gradually evolve based on previous norms, sometimes there genuinely can be concern about a “slippery slope” taking hold, where enabling one kind of shift to social norms will lead to another similar kind of shift to social norms: for instance, “grade inflation” over the decades has changed the significance of different grades in a classroom as social norms generally shift. But there mere fact that there are no sharp ways to draw a boundary does not in itself guarantee a society will progress through every step of the slippery slope.
Submodule 3.3 Practice Quiz
Licenses and Attributions
Key Sources:
- Watson, Jeffrey (2019). Introduction to Logic. Licensed under: (CC BY-SA).
Next Page: 4.1 The Form of an Argument