Circular Argument
A logical fallacy where two unproven claims are used to support each other, or the conclusion is assumed within a premise, creating a reasoning loop with no independent evidence.
THE IDEA
Definition
Circular argument, also known as petitio principii or begging the question, occurs when an argument's conclusion is assumed in one of its premises, or when two statements are each used to prove the other, with neither having independent support. This creates a logical loop where no real evidence is presented.
Structure
- Premise 1: X is true because Y is true (Y unproven).
- Premise 2: Y is true because X is true (X unproven).
- Conclusion: Therefore, X and Y are true.
Common Example
"You can't give me a C on this paper! I'm an A student! And A students don't get C's." The claim "I'm an A student" is treated as enough to establish the grade. This is circular if that status is itself justified by assuming papers like this must receive an A. Earlier grades would be independent evidence of past performance, but would not by themselves establish this paper’s grade.
Why is it fallacious?
Circular reasoning provides no independent verification; it simply restates the claim in different words. It gives the illusion of an argument but fails to offer real support.
When to use it
Evaluating a company's claim: 'Our product is the best because it's the top-selling, and it's top-selling because it's the best.'
Debating a religious argument: 'God exists because the Bible says so, and the Bible is the word of God.'
Assessing a student's claim: 'This paper deserves an A because it is A-quality, and it is A-quality because it deserves an A.'
Self-justification: 'I'm a good person because I do good things, and those things are good because I do them.'
FROM THEORY TO EVERYDAY LIFE
In practice
The A Student's Argument
"You can't give me a C on this paper! I'm an A student! And A students don't get C's."
Opium's Dormitive Virtue
Opium causes sleep because it has a dormitive virtue, which is the property of causing sleep.
A MOMENT TO REFLECT
Put it to work.
When you next argue for a belief, can you identify whether your reasoning relies solely on restating that belief in different words?
In a discussion, if someone says 'X is true because Y, and Y is true because X,' how would you point out the circularity?
Examine a political opinion you hold: do you have independent evidence for each step, or does it form a closed loop?
CONTINUE THE CONVERSATION
Source texts
- Wisdom Theory 100 Mental Models (2020) (Wisdom Theory)