Inconsistency
Inconsistency is a logical fallacy where one or more propositions are asserted that cannot all be true. It also refers to holding multiple views or beliefs that cannot all be true simultaneously.
THE IDEA
Inconsistency
(also known as: kettle logic [form of], internal contradiction [form of], logical inconsistency [form of])
Description: In terms of a fallacious argument, one or more propositions are asserted that cannot both possibly be true. In a more general sense, holding one or more views/beliefs that cannot be all true together.
The original argument statements and the kettle’s proposed defenses are absent. The commentary below does not substitute for those missing premises.
Example #1:
Explanation: The commentary alleges that a creationist rejects science while defending “creation science” through “scientific evidence”. To establish a contradiction, identify precisely what the person rejects and accepts. Rejecting a particular scientific theory while using a computer is not, by itself, a formal contradiction.
Example #2:
Explanation: The commentary gives two assertions: 1) God is pure love and 2) he is the creator of everything. A contradiction would require additional premises about what pure love can create or permit and what counts as creation. The listed assertions alone do not make that argument explicit.
Exception: One needs to be able to explain how the beliefs are not inconsistent.
Tip: Think about your beliefs. Are there any inconsistent with each other? With how you act and what you do?
Variation: The internal contradiction is a blatant contradiction in the same argument (thus “internal”). Kettle logic is usually multiple, contradicting arguments, supporting a single point. In an example used by Sigmund Freud in The Interpretation of Dreams, a man accused by his neighbor of having returned a kettle in a damaged condition offered three defenses, whose wording is missing here.
A logical inconsistency usually refers specifically to inconsistencies in formal, or deductive, logic.
When to use it
Debating: Ensure all your points support a consistent conclusion.
Self-reflection: Examine your core beliefs for contradictions to improve intellectual honesty.
Evaluating theories: Look for internal inconsistencies in scientific or philosophical theories.
Detecting manipulation: Identify when someone uses contradictory arguments to defend a position.
FROM THEORY TO EVERYDAY LIFE
In practice
Creationist inconsistency
The commentary alleges a conflict between rejecting science and appealing to “creation science” and “scientific evidence”. Assess the precise claims; selectively accepting theories or using scientific technology does not by itself establish a contradiction.
God and hate inconsistency
The source alleges a contradiction between divine love and the creation of hate. That requires premises connecting love, creation, and permission; disagreement with either assertion alone does not establish logical inconsistency.
A MOMENT TO REFLECT
Put it to work.
Can you recall a time when you held two beliefs that turned out to be inconsistent? How did you resolve it?
When constructing an argument, how can you systematically check for contradictions among your premises?
Think of a common inconsistency you observe in politics or advertising—what makes it fallacious?
CONTINUE THE CONVERSATION
Source texts
- Logically Fallacious - The Ultimate Collection of Over 300 Logical Fallacies