Appeal to Common Belief
An appeal to common belief treats a claim’s popularity as sufficient reason to accept it. The key question is whether the belief rests on evidence, including evidence assessed by relevant experts.
THE IDEA
Appeal to Common Belief
argumentum ad populum (also known as: appeal to accepted belief, groupthink, appeal to widespread belief, appeal to the masses, appeal to belief, appeal to the majority, argument by consensus, consensus fallacy, authority of the many, bandwagon fallacy, argumentum ad numerum, appeal to the number, argumentum consensus gentium, appeal to the mob, appeal to the gallery, mob appeal, social conformance, value of community)
Description: When the claim that most or many people in general or of a particular group accept a belief as true is presented as evidence for the claim. Popularity alone does not establish truth; ask what evidence supports the belief.
Logical Form:
- Person 1 says that most people believe X.
- Therefore, X is true.
Example #1: Up until the late 16th century, most people believed that the earth was the center of the universe. This, of course, is not true.
Explanation: The geocentric model was observation (limited) and faith based, but most who accepted the model did so based on the common and accepted belief of the time, not on their own observations, calculations, and or reasoning. It was people like Copernicus, Galileo and Kepler, who refused to appeal to common belief and uncovered a truth not obvious to the rest of humanity.
Example #2: The source omits the argument for this example.
Explanation: It discusses belief in virgin births, but faith alone is a different basis for belief from popularity. An appeal to common belief would argue that the claim must be true because many people accept it.
Exception: Sometimes there is good reason to think that the common belief is held by people who do have good evidence for believing. As a hypothetical example, if 99.7% of all earth scientists believe that the universe is approximately 13.7 billion years old, it is wise to believe them, because they will be able to present objective and empirical evidence as to why they believe.
Tip: Apply the same evidential standard to popular and unpopular claims. Disagreeing with a majority does not by itself make a claim more credible.
When to use it
A political campaign claims a candidate is best because 'everyone is saying so' – examine the evidence behind the claim.
A marketing campaign uses 'most people prefer our product' as a selling point – check for independent studies.
In a workplace, a team adopts a common practice simply because 'that’s how it’s always been done' – evaluate its actual effectiveness.
On social media, a viral story is accepted as true because of its popularity – verify with reliable sources.
FROM THEORY TO EVERYDAY LIFE
In practice
Geocentric Model Belief
The source uses the acceptance of geocentrism until the late 16th century to illustrate that a belief can be widespread and false. Its popularity did not settle the astronomical question; observations and models had to be compared.
Belief in Virgin Births
Arguing that virgin births must occur because many people believe in them appeals to popularity. Merely saying that the belief is held on faith does not, by itself, make that particular argument.
A MOMENT TO REFLECT
Put it to work.
Think of a time you accepted a popular opinion without questioning its evidence. How did that affect your understanding?
How can you tell the difference between a consensus based on sound evidence and one based on mere popularity?
What historical beliefs were once widely held but later proven false? How might you avoid being misled by current popular beliefs?
CONTINUE THE CONVERSATION
Source texts
- Logically Fallacious - The Ultimate Collection of Over 300 Logical Fallacies