In everyday arguments—whether in essays, debates, or advertisements—people often try to persuade us by making appeals. These appeals can be powerful tools of reasoning, but they can also be misleading if used incorrectly.
Let’s explore the most common types of appeals and how to tell when they strengthen an argument—or weaken it.
Appeal to Authority - This is when someone supports their argument by referring to an expert or someone with relevant knowledge.
✅ Valid Use: Referring to a recognized expert in the relevant field.
“According to Dr. Lee, a climate scientist, global temperatures are rising.”
❌ Flawed Use: Referring to a celebrity or someone outside their area of expertise.
“A famous actor says this diet works, so it must be true.”
Even when the authority is relevant, remember: experts can disagree, and even a consensus should be open to questioning.
✅ Valid Use: A teacher or examiner has the right to judge the quality of your essay—even if your friends think it’s great.
2. Appeal to Popularity - This is when something is claimed to be true or good just because many people believe it or do it.
✅ Reasonable Use: Popularity can be relevant in some contexts, like marketing or elections.
“Most people read the astrology column, so we should include one in our paper.”
❌ Flawed Use: Assuming something is true just because it’s popular.
“Astrology must be true—everyone reads it!”
3. Appeal to History -This is when past experiences are used to predict or justify future actions.
✅ Valid Use: Learning from past mistakes or patterns.
“Last time I walked across that frozen lake, I fell in. I’m not doing that again.”
❌ Flawed Use: Assuming the past always predicts the future, or using outdated history to justify current decisions.
“Prisons were originally just holding cells before execution, so we shouldn’t use them now.”
4. Appeal to Tradition - This is when something is defended just because it’s always been done that way.
✅ Reasonable Use: Tradition can be practical and efficient.
“We’ve always used this method, and it works well.”
❌ Flawed Use: Using tradition as an excuse to avoid change or improvement.
“We’ve always done it this way, so we shouldn’t change it—ever.”
5. Appeal to Novelty - This is the opposite of tradition—assuming something is better just because it’s new.
❌ Flawed Use: New doesn’t always mean improved.
“This is the new version of the product, so it must be better.”
6. Appeal to Emotion - This is when arguments try to persuade by triggering feelings like fear, pity, guilt, or pride.
✅ Valid Use: Emotion can be appropriate if it supports a logical point.
“Imagine how hard it is for families who can’t afford healthcare.”
❌ Flawed Use: Emotion is used to manipulate rather than reason.
“If you don’t support this policy, you must not care about children.”
It is a weakness if reasoning supports only part of the conclusion which is drawn from it, or if a moderate claim or intermediate conclusion is used to support a conclusion which would follow only from a stronger version.
It is a weakness if one part of an argument's reasoning contradicts, or is inconsistent with, another part.
This is the first paragraph of an argument about change. The final paragraph ofthat argument, including the main conclusion, is:
Admittedly, some changes do ultimately turn out to have been for the better, but the problem is that we cannot tell beforehand which ones they will be. It is always more likely that any particular proposal will lead to catastrophe than that it will result in an improvement. So the best practice is to be safe, by resisting all change. This reasoning is weakened by two inconsistencies.
This reasoning is weakened by two inconsistencies.
The word 'improvement' is used in different senses in the two paragraphs. The point being made in the first paragraph, that changes which are called 'improvements' often (or 'always') do not make things better, is weakened by the use of the word in its usual sense in the final paragraph. Since this inconsistency makes the overall argument less clear than if the word had been used consistently, it was probably unintentional.
The more serious weakness is that the first sentence claims that all changes are for the worse, while the final paragraph admits that some changes are for the better. The support which the first paragraph gives to the conclusion is weakened by this concession.
Arguments often make use of analogies, in which an unfamiliar concept is illustrated by reference to something more familiar. Politicians frequently use analogies, for example, 'Managing the budget of a country is just like managing the budget of a household: you can't spend more than you earn.' It is not a valid criticism of an analogy to say that the two entities are different, because that is the whole nature of an analogy. Even imperfect analogies can strengthen an argument, but a wild analogy which lacks significant points of similarity or has crucial differences constitutes a weakness in reasoning.
An example of a weak or false analogy is that tobacco is like arsenic, because both of them kill people, and therefore the sale of tobacco should be controlled by the Poisons Act. The weakness of this analogy is that the differences between arsenic and tobacco are crucial to the issue. No one consumes arsenic for pleasure; the harm done by smoking tobacco products is indirect, long term and a matter of risk rather than certainty.
It is not a weakness for an argument to be one-sided. Someone defending one point of view is under no obligation to show balance.
But it can be a weakness if the proponent fails to foresee and respond to an obvious objection to a claim or line of reasoning, because this omission may cause most of the audience or readership to reject the argument.
The use of a counter assertion or counterargument with a response can be an effective technique in an argument, but giving the counter without responding to it weakens the argument, because it is doing the work of opponents for them.
Many flaws and weaknesses can be alternatively expressed in terms of assumptions, and that approach is just as acceptable as identifying the technical term.