The appeal to definition (also known as the argument from dictionary) is a logical fallacy that occurs when someone’s argument is based, in a problematic manner, on the definition of a certain term as it appears in a dictionary or a similar source.
The main problem with such arguments is that dictionaries are descriptive in nature, rather than prescriptive, meaning that they attempt to describe how people use the language, rather than instruct them how to do so in a definitive manner.
Accordingly, dictionary definitions don’t always reflect the meaning of words as they’re used by people in reality. This can happen for various reasons, such as that the dictionary definition doesn’t list all the connotations of a word, or that the dictionary definition doesn’t capture the new meaning of a word that has been recently turned into slang.
Furthermore, another notable problem with appeals to definition is that different dictionaries can list different definitions for a given term, and even a single dictionary can have multiple definitions for the same term.
Accordingly, it’s generally fallacious to claim that any single definition is the right one. Furthermore, in many cases, such claims involve fallacious cherry-picking, where people pick the definition that best supports their stance out of the ones available to them, while ignoring others.
Because the appeal to definition is problematic, and because this fallacy is frequently used in discussions on various topics, it’s important to understand it. As such, in the following article you will learn more about the appeal to definition, and see how you can respond to people who use it.
Examples of the appeal to definition
One example of the appeal to definition is the following:
Alex: this restaurant is freezing.
Bob: the dictionary says that ‘freezing’ means “being at the temperature at which water turns into ice or below it”, and it’s clearly not that cold here.
Here, Bob is using the appeal to definition when he claims that Alex’s statement is wrong, by using a dictionary definition of the term “freezing”, that doesn’t reflect the meaning of the term that Alex meant to convey (which is along the lines of “very cold”). This also represents an example of cherry-picking, since most dictionaries (such as the Merriam-Webster Dictionary and the Cambridge Dictionary) also contain the meaning of the term that Alex meant to convey for the term “freezing”, often as its main definition.
Another example of the appeal to definition is the following:
“We should ignore the theory of evolution, because the dictionary says that a theory is just an opinion that you have about something you can’t prove.”
In this example, the person using the appeal to definition is relying on a specific definition for the word “theory” in order to argue against the theory of evolution. This argument is fallacious, because it ignores alternative definitions of the term “theory”, which more accurately capture the meaning of the term as it’s generally used in the scientific context.
This issue is evident both when it comes to alternative definitions for this term within the same dictionary that was used to support the definition above (Collins Dictionary), as well as when it comes to other dictionaries, such as the Merriam-Webster dictionary, in which one of the definitions for the term “theory” is “a plausible or scientifically acceptable general principle or body of principles offered to explain phenomena”.
Note: the appeal to definition is sometimes referred to using other names, most notably the argument from dictionary, but also argumentum ad dictionarium, the dictionary fallacy, and the definition fallacy.
How to respond to an appeal to definition
When responding to an appeal to definition, it’s important to remember that not every use of a definition is necessarily fallacious in nature. Rather, as long as the use of the definition is properly justified, and as long as the definition is selected in a way that’s also properly justified, then the use of the definition is generally not fallacious.
Accordingly, the use of a dictionary definition in an argument, or of any other definition, is generally fallacious only when at least one of the following conditions are true:
- There is no valid reason for using the definition, for example because the dictionary definition is not expected to capture the connotations that the term in question has.
- The definition is flawed or was selected in a flawed way, for example because it was cherry-picked out of a range of available definitions.
If, based on these conditions, you believe that an argument represents a fallacious appeal to definition, then you counter it using two main approaches:
- Explain why the use of the definition is inappropriate in this case. For example, you can explain why you shouldn’t expect a dictionary definition to accurately capture all the connotations of a certain word.
- Explain why the proposed definition is flawed. For example, you can show that other dictionaries propose different definitions than the one that your opponent has chosen to use in their argument.
In addition, you can sometimes benefit from using specific, relevant examples to illustrate why the use of such arguments is problematic. Furthermore, you can also ask the person using the fallacy to properly justify their reasoning, especially in light of your criticism, which can sometimes help them see the logical issues with their argument.
Finally, note that in some cases people might refuse to stop using their preferred definition, even when you demonstrate that its use is fallacious. When this happens, it’s up to you to decide whether the use of the definition is so problematic that it shuts down any chance of discourse, or whether you want to simply ignore their fallacious argumentation for the sake of the discussion.
Overall, to properly respond to an appeal to definition, you should first make sure that the use of the definition is fallacious, and then either explain why the use of definition is inappropriate in this case, or why the proposed definition is flawed. In addition, you can also use other relevant techniques, such as using relevant examples to illustrate the problem with this type of argument.
Note: when responding to appeals to definition, two related terms that are useful to know are denotation, which is the primary or literal meaning of a word, and connotation, which is a feeling or idea that a word evokes beyond its denotation.
The appeal to definition and non-dictionary definitions
Though the appeal to definition generally involves the direct use of a dictionary definition, this isn’t always the case. Rather, people sometimes use this fallacy when they claim that the term in question is defined a certain way according to a similar type of source, such as some authority figure in the field. In such cases, the person using this fallacy might use vague language, and claim that this is how this term is defined, without giving a clear source, by using statements such as “they say that this term means…”.
However, keep in mind that, as with dictionary definitions, there are also situations where people use non-dictionary definitions in their arguments in an entirely reasonable manner. As such, just because someone uses a non-dictionary definition in their argument, that doesn’t necessarily mean that their argument is fallacious.
The appeal to definition and modern dictionaries
As new technologies developed, the structure and use of dictionaries have changed, and this has some implications for how appeals to definition are used, and how you can respond to them.
First, it is now far easier to look for dictionary definitions than it used to be in the past, due to the availability of easily accessible online dictionaries.
This makes it easier for people to use dictionary definitions in their arguments, and also makes it easier for people who do so to cherry-pick their preferred definition out of all the available ones. At the same time, however, this also makes it easier for those responding to appeals to definition to identify issues with the definitions used in those arguments, for example by showing that they contradict definitions that appear in other dictionaries.
In addition, technological changes have also led to the development of dictionaries that can be rapidly updated with new words or with new meanings of existing words. Furthermore, the use of online dictionaries removed most of the space constraints that paper dictionaries had, which allows dictionaries to list a wider range of meanings and connotations than they used to. This means that dictionaries are often better able to describe the use of language than they used to, which makes them into more valid sources for definitions in some cases.
How to avoid using the appeal to definition yourself
As noted above, it can sometimes be reasonable to use definitions from dictionaries and similar sources in your argument. For example, if someone attacks the theory of evolution because it’s a “just a theory”, you can explain that in the scientific context, the term “theory” means something else than what it means in everyday situations, and use the dictionary definition of the term to support that.
As such, if you do decide to use a dictionary definition as part of your argument, then you need to ensure that you’re not using it in a fallacious manner. To do this, you should make sure that:
- There is a valid reason for including the definition in your argument.
- The definition was selected in a reasonable manner, that doesn’t involve cherry-picking.
In general, it’s preferable to explicitly explain both why you’re including the definition in your argument and how you picked it. This will help you ensure that you’re using the definition in a reasonable manner, and will help the people you’re discussing the topic with understand the reasoning behind your use of the definition.
Types of definitions
There are different types of definitions that people can use. While understanding them is not crucial to being able to understand the appeal to definition, it is a way to learn more about the topic, and about the various reasonable and fallacious ways in which people use definitions in their arguments.
Main types of definitions associated with the appeal to definition
There are several types of definitions that are especially useful to understand in the context of the appeal to definition.
First, there are reportive definitions. A reportive definition (also referred to as a lexical definition or dictionary definition) is a definition that aims to accurately capture the meaning of a term as it’s ordinarily used, in a clear and concise manner. For example, a reportive definition of the word “freezer” could be “a refrigerated cabinet or room for preserving food at very low temperatures”. Reportive definitions are usually focused on the literal meaning of terms, and often leave out figurative meanings or connotations.
Second, there are precising definitions. A precising definition is a definition that adds relevant criteria to a reportive definition in order to make it more precise for a specific purpose. For example, if the reportive definition of “resident” is “someone who lives in a certain place”, a precising definition of the term for legal purposes might be “someone who spends at least 180 days of the year in a certain location”.
Third, there are stipulative definitions. A stipulative definition is a definition that someone establishes for a specific purpose. For example, establishing a stipulative definition may involve saying “for the purpose of the present document, the term ‘contract’ will have the following meaning…”.
However, the fact that stipulative definitions exist does not mean that people can, in a reasonable manner, make up whatever definition they want for existing terms in any situation. Doing so is referred to as the Humpty-Dumpty theory of meaning, based on the novel ‘Alice in Wonderland’, where the character Humpty Dumpty says that words can mean whatever he wants them to mean, and is problematic, since it can lead to serious issues in communication.
Furthermore, this approach can be problematic when people attempt to win debates by simply stipulating definitions that support their stance, without using proper evidence or reasoning, a fallacious technique known as victory by definition.
Finally, there are persuasive definitions. A persuasive definition is a stipulative definition that’s disguised as a reportive definition, in order to present one’s preferred definition for something as if it was an accepted fact, in a situation where that’s not the case.
Persuasive definitions are often used when it comes to emotionally charged words, and their use frequently involves keeping the emotional connotations of a word while altering its main meaning. In addition, persuasive definitions are often modified with qualifiers such as “real” or “true”, as in the case of “true socialism means…”. Using a persuasive definition is sometimes also referred to as the persuasive definition fallacy, the definist fallacy, or redefinition.
Note: an overview of the various types of definitions is available in philosopher Trudy Govier’s textbook “A Practical Study of Argument”. The concept of persuasive definition in particular is attributed to philosopher Charles Stevenson’s 1938 paper on the topic.
Other types of definitions
In addition to the types of definitions described above, which are the main ones that play a role in the appeal to definition fallacy, there are other types of definitions that people use, both in relation to the appeal to definition and in general. This includes, most notably, the following:
- Ostensive definitions. An ostensive definition is a definition that’s based on examples of the word that’s being described. For example, the ostensive definition of the word “liquid” could be “things like water and oil”. Note that, in cases where the examples in this definition are literally pointed out in reality, this can also be referred to as definition by pointing. This type of definition can be used in a fallacious manner, similarly to a stipulative definition.
- Misleading definitions. A misleading definition is a definition that relies on misleading language, so that its intended meaning is different than the meaning that most people will assign to it. For example, a sales pitch might use a misleading definition for a term, so that people will think that it means one thing when in reality it means something else.
- Operational definitions. An operational definition is a definition that’s used to define a certain measure, such as ‘temperature’ or ‘intelligence’, generally based on the procedure used to determine it in a particular context. Operational definitions are a subtype of stipulative definitions, and are most commonly found in places where an exact, reproducible definition is needed, such as in scientific studies. However, note that such definitions can be flawed, for example if the operation in question doesn’t accurately measure what it’s supposed to be measuring.
Related concept: quibbling
In the context of logic, quibbling occurs when someone attacks an argument in a fallacious manner, by addressing one of the terms in the argument based on a different meaning than was originally intended. This is described in the following quote:
“A dispute between two people is a conversation in which one of them argues for, and the other argues against, a certain conclusion. Now, suppose A gives a reason for a statement, using a certain term in one sense, and B gives a reason against the statement, using the same term in a different sense. Then B is quibbling on the term.”
— From ‘Thinking Straight‘ (Beardsley, 2013)
Quibbling is often used in conjunction with the appeal to definition, when someone uses the appeal to definition while quibbling regarding a term that appears in their opponent’s argument.
Summary and conclusions
- The appeal to definition is a logical fallacy that occurs when someone’s argument is based, in a problematic manner, on the definition of a certain term as it appears in a dictionary or a similar source.
- For example, if one person says “this restaurant is freezing” and someone replies by saying “the dictionary says that ‘freezing’ means ‘being at the temperature at which water turns into ice or below it’, and it’s clearly not that cold here”, that person is using the appeal to definition.
- The main problem with such arguments is that dictionaries don’t necessarily reflect exactly how speakers use language in reality; this is evident, for example, in the fact that dictionary definitions often don’t list all the connotations of words.
- Another issue with such arguments is that a given term can have more than one definition, which is why it’s fallacious to assume that any single definition is the only right one, and which is why this sort of argument often involves fallacious cherry-picking, where people choose only the definition that best supports their argument.
- To respond to an appeal to definition, you should first make sure that the use of the definition is fallacious, and then either explain why the use of definition is inappropriate, or why the proposed definition is flawed; you can also use relevant examples to illustrate the problem with this type of argument, and ask your opponent to justify their reasoning.