Alleged Certainty
Asserting a conclusion without evidence or premises, through a statement that makes the conclusion appear certain, when in fact, it is not.
THE IDEA
Alleged Certainty
(also known as: assuming the conclusion, appeal to common sense [form of])
Description: Asserting a conclusion without evidence or premises, through a statement that makes the conclusion appear certain, when in fact, it is not.
Logical Form: A symbolic form is not supplied. The examples show assertions whose apparent certainty substitutes for support.
Example #1:
“Everyone knows that it’s wrong to kill another person.”
Explanation: Actually, people everywhere don’t recognize this. This may seem like common sense to those who make the claim, and to many who hear the claim, but there are many people on this earth who do not share that view, and need to be convinced first.
Example #2:
“Everyone knows that there are no universal truths.”
Explanation: The speaker has not established that everyone accepts the claim. Agreement within a social circle is not evidence of universal agreement, and neither establishes the claim’s truth.
Exception: Facts that would seem foolish not to assume, can be assumed – but one should be prepared to support the assumption, no matter how certain one may be.
Tip: For empirical judgments that remain uncertain, consider replacing “certain” with “extremely probable”. The wording should reflect the evidence; it need not weaken a valid deduction.
Variation: The appeal to common sense is asserting that your conclusion or facts are just “common sense”, yet sense is anything but common. We have a tendency to think that many of our beliefs and opinions are “common sense” when in fact they are not. We must argue as to why we believe something is common sense, rather than just asserting that it is.
When to use it
In a debate, when someone asserts a claim as universally accepted without providing evidence.
In advertising, when a product is claimed to be 'obviously better' or 'what everyone wants' without supporting data.
In politics, when a policy is presented as 'common sense' without addressing differing perspectives or evidence.
In everyday conversation, when using phrases like 'everyone knows that...' to avoid justifying a position.
FROM THEORY TO EVERYDAY LIFE
In practice
Everyone knows that it’s wrong to kill another person.
Actually, people everywhere don’t recognize this. This may seem like common sense to those who make the claim, and to many who hear the claim, but there are many people on this earth who do not share that view, and need to be convinced first.
Everyone knows that there are no universal truths.
Acceptance within one social circle does not establish universal agreement. More importantly, claiming that everyone accepts a statement does not provide the missing argument for its truth.
A MOMENT TO REFLECT
Put it to work.
Think of a belief you hold as certain. How would your reasoning change if you replaced 'certain' with 'extremely probable'?
When you hear someone say something is 'common sense', what arguments could you ask them to provide to support that claim?
Recall a time you assumed everyone shared your viewpoint. How might that assumption have led to faulty reasoning?
CONTINUE THE CONVERSATION
Source texts
- Logically Fallacious - The Ultimate Collection of Over 300 Logical Fallacies