Begging the question

From RationalWiki

Begging the question or assuming the answer is a logical fallacy that occurs when the conclusion of an argument is used as a premise of that same argument; i.e., the premises would not work if the conclusion is invalid.^[1] It is often called circular reasoning, although sometimes it's considered distinct with the distinction that circular reasoning is: "A implies B which implies A", whereas "begging the question" is that "A implies B and A is only valid because B is assumed".

Circular reasoning is fallacious because reasoning and justification must start with the known and then determine the unknown - in the case of circular reasoning, it starts with the known and ends up with the equally known, thus it proves nothing.^[2]

Contents 1 Examples 2 Confusion with term 3 Spherical logic 4 See also 5 Footnotes

[edit] Examples

Example 1:

• We shall prove that God exists.

1. The order and magnificence of the of the world is evidence of God's Creation.
2. Therefore, we know that God exists.

Here, it is assumed that God exists in order to satisfy the premise that "God's Creation" is evidence of his existence. There is no standalone argument here that connects existence to God's creation except the conclusion, which is that God exists. Note the slight structural differences in the argument to simple circular reasoning - the order of the world isn't implied by God's existence, but trying to use it as evidence of God's existence must assume he exists in the first place.

Example 2:

• We shall justify making abortion illegal.

1. Abortion is unjust murder.
2. Murder is illegal.
3. Therefore abortion should be made illegal, since it is murder.

In this case, the conclusion (that abortion should be illegal because it is murder) is assumed to be true in order to compare it to murder in the first point. Essentially, the initial premise comparing abortion to murder remains unproved without any additional evidence.

[edit] Confusion with term

Warning: Pedantry Alert

Many people incorrectly use the expression "begs the question" to mean "raises the question" - in the sense that they believe an important point is being overlooked in the argument given. For example; "If God created the universe, this begs the question of who created God." In this case, "raises the question" is the correct term to use. There are countless of examples of this use, and pointing it out is best handled by professional and qualified pedants only.

[edit] Spherical logic

Spherical logic can be expressed mathematically as:

[edit] See also

• Not Circular Reasoning — an example of circular reasoning from CMI.

[edit] Footnotes

1. ↑ Skeptic's Dictionary - Begging the question
2. ↑ What Is Circular Reasoning? (PDF)

Articles about logical fallacies
Formal fallacies
Ad hominem	Argument by assertion	Negative proof	Non sequitur
Informal fallacies
Ad hoc	Argumentum ad nauseam	Argumentum ex culo	Argument from ignorance	Argument from incredulity	Balance fallacy
Begging the question	Correlation does not equal causation	Equivocation	False analogy	False dilemma	Moving the goalposts
No True Scotsman	One single proof
Red herrings
Argumentum ad baculum	Argumentum ad populum	Argument from adverse consequences	Association fallacy	Bullshit	Poisoning the well
My enemy's enemy	Spotlight fallacy	Straw man	Style over substance fallacy	Texas sharpshooter fallacy
Conditional fallacies
Argument from authority	Galileo gambit	Slippery slope
Fallacious argument styles
Chewbacca Defense	Gish Gallop	Ham Hightail	JAQing off