Accused of a fallacy? Suspect a fallacy? Ask Dr. Bo and the community!

Quickly register to comment, ask and respond to questions, and get FREE access to our passive online course on cognitive biases!

one moment please...

Fallacy of Division

(also known as: false division, faulty deduction, division fallacy)

Description: Inferring that something is true of one or more of the parts from the fact that it is true of the whole.  This is the opposite of the fallacy of composition.

Logical Form:

A is part of B.

B has property X.

Therefore, A has property X.

Example #1:

His house is about half the size of most houses in the neighborhood. Therefore, his doors must all be about 3 1/2 feet high.

Explanation: The size of one’s house almost certainly does not mean that the doors will be smaller, especially by the same proportions.  The size of the whole (the house) is not directly related to the size of every part of the house.

Example #2:

I heard that the Catholic Church was involved in a sex scandal cover-up.  Therefore, my 102-year-old Catholic neighbor, who frequently attends Church, is guilty as well!

Explanation: While it is possible that the 102-year-old granny is guilty for some things, like being way too liberal with her perfume, she would not be guilty in any sex scandals just by her association with the Church alone.

Exception: When a part of the whole has a property that, by definition, causes the part to take on that property.

My 102-year-old neighbor is a card-carrying member of an organization of thugs that requires its members to kick babies.  Therefore, my neighbor is a thug... and she wears way too much perfume.


Goodman, M. F. (1993). First Logic. University Press of America.

Registered User Comments

Thursday, January 10, 2019 - 11:07:05 AM
The 102-year-old neighbor wearing way too much perfume is not relevant to the argument. In addition, the phrase "way too much" is highly subjective, isn't it?

login to reply
0 replies
0 votes
Reply To Comment

Tuesday, September 11, 2018 - 07:56:09 PM
This is an argument I saw on Facebook in the aftermath of the metoo movement.

Men(plural) oppress women, therefore all individual men oppresses all individual women.

Perhaps men as a group do oppress women as a group. Let’s say this is true. Oppression by men plural is different than what can be meted out by a single man. I suppose an individual man could oppress an individual woman, but I think it is a fallacy of division to think that because men as a group oppress women, it is also true that all individual men oppress all individual women. You could have a situation where men as a group oppress women as a group but this one man does not necessarily oppress this one woman.

login to reply
0 replies
1 votes
Reply To Comment

Tuesday, August 14, 2018 - 08:34:33 AM
I see a bit of 'the ecological fallacy and guilt by associaton fallacy' in this fallacy.

login to reply
0 replies
1 votes
Reply To Comment

Become a Logical Fallacy Master. Choose Your Poison.

Logically Fallacious is one of the most comprehensive collections of logical fallacies with all original examples and easy to understand descriptions; perfect for educators, debaters, or anyone who wants to improve his or her reasoning skills.

Get the book, Logically Fallacious by Bo Bennett, PhD by selecting one of the following options:

Not Much of a Reader? No Problem!

Enroll in the Mastering Logical Fallacies Online Course. Over 10 hours of video and interactive learning. Go beyond the book!

Enroll in the Fallacy-A-Day Passive Course. Sit back and learn fallacies the easy way—in just a few minutes per day, via e-mail delivery.

Have a podcast or know someone who does? Putting on a conference? Dr. Bennett is available for interviews and public speaking events. Contact him directly here.

About Archieboy Holdings, LLC. Privacy Policy Other Books Written by Bo
 Website Software Copyright 2019, Archieboy Holdings, LLC.