Fallacy of division is a logical fallacy – and more specifically, an informal fallacy – that arises when the attributes of a whole are mistakenly presumed to apply to the parts, or members, of the whole. It is the converse of the fallacy of composition.
It is also known as “false division” and “faulty deduction”.
The fallacy of division, as well as the fallacy of composition, originated with the Greek philosopher Aristotle who wrote about them in his Sophistical Refutations, which is considered to be the first work to address logical fallacies and deductive reasoning.
Definition
The fallacy of division occurs when someone argues that something which is true of the whole, must also necessarily be true of each or some parts of the whole.
In other words, it is based on the fallacious assumption that the attributes of the larger group and its members are transferable from one to the other.
As such, its logical form is:
- X is part of Y.
- Y has property A.
- Therefore, X has property A.
An example of the fallacy of division would be:
- “The United States is one the richest countries in the world: Therefore, everyone living in the United States must be rich”.
Here, the fallacy occurs because it is falsely inferred that everyone living in the United States is rich from the fact that the country is rich.
Examples
- “The most popular sport in England is soccer. Tom is English. Therefore, Tom’s favorite sport is soccer.”
- “An aircraft can fly thousands of kilometers without landing, and they are made of aluminum materials. Therefore, aluminum materials can fly thousands of kilometers without landing.”
- “Because religions have caused so much evil and suffering in the history of humankind, every religious individual must be inherently malicious”.
- “That soccer team is one of the best teams of all-time. Therefore, every single player on that team is one of the best players of all-time.”
- “A colony of ants can build a mound up to 2,5 meters high. Therefore, this ant can build a mound that high.”
- “Men are faster runners than women, therefore my brother must be faster than my sister.”
- “If your brain is the source of your consciousness, then every cell of your brain must have consciousness.”
- “If water (H2O) is liquid, then both hydrogen and oxygen must also be liquid.”
- “Trees are visible, and trees are made of atoms. Therefore, atoms are also visible.”
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