Petitio Principii

"Begging the Question"

If communicators assume as evidence for their argument the very conclusion they are attempting to prove, they engage in the fallacy of petitio principii, also known as "begging the question."

People often use the term "that begs the question" differently than it is used when discussing logic, so please be sure to know the difference between the two uses.

The most common form of this fallacy is when the first claim is initially loaded with the very conclusion one has yet to prove.

 For example, suppose a particular student group states: "Useless courses like AP English Language & Composition should be dropped from QSI Haiphong's curriculum because nobody wants the school to spend money on useless courses.

Yes, we can all agree that spending money on useless courses is unacceptable; however, the arguers never did prove that AP Language & Composition was itself a "useless course." They merely "begged the question" and moved on to the safe part of the argument. They skipped past the portion of the argument that is the real controversy and deserves more debate.

Begging the question is often hidden in the form of a complex question. When a question is complex--containing two or more parts--it can be difficult for the opposition to respond to thoughtfully. They have to remember all of the parts and address them separately. The more complex the question is, the more difficult it is to respond to effectively, especially when in a high-pressure situation.

Example: "Because the American education system is broken, we should create a new system that acknowledges different learning styles and can reach every student."

This begs the question as to whether the American education system is actually broken. The person making the above statement clearly feels that the American education system is broken and includes that stance in the suggestion that we should do things differently. 

If the respondent believed that the American education system was NOT broken, they would need to split this discussion into two parts: 

Part 1 would need to be argumentative and state that the system is NOT broken.

Part 2 would most likely agree that acknowledging different learning styles and reaching each student is valuable.


Just some neighborhood kids "discouraging violent crime.".

Example: "We must institute the death penalty to discourage violent crime."

This begs the question: Does the death penalty actually discourage violent crime? 

Of course, we don't want violent crime, but what actually deters it?


(Adapted from: http://www.brainpickings.org/index.php/2014/01/03/baloney-detection-kit-carl-sagan/)

Example: "Why would you vote for that socialist, Obama, since none of us want an anti-American in the White House?"

This loaded question begs needs to be broken into several pieces to be addressed independently: 

Part 1, a respondent must ask if Obama is a socialist or not.

Part 2, they must ask if socialism should even be considered "anti-American." 

Part 3, they could then acknowledge that, sure, nobody wants an anti-American to be the American president. Duh. 

This petitio principii moves quickly past Parts 1 & 2, forcing the respondent to responsibly say, "Wait a minute! Not so fast! Let's discuss what you just said piece-by-piece."