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Line 1: − [[Circular reasoning]] is a form of [[Logical fallacy#Proof by assertion|proof by assertion]] in which one assumes the fact that one is trying to prove, and then "proves" the fact by a chain of inferences that lead back to the original assertion. This is also known as ''petitio principii'' or ''begging the question.''+ − − == An analysis == − The simplest argument is a single inference, as per the Law of Detachment: − − *If P, then Q. − *P. − *Therefore, Q. − − The Law of the Syllogism uses Detachment to establish an ''intermediate'' conclusion between the original premise and the eventual conclusion. Thus: − − *If P, then Q. − *If Q, then R. − *Therefore, if P, then R. − *P. − *Therefore, Q and R. − − ''Contraposition'' uses Detachment in reverse to show that a thing is ''not'' true: − − *If P, then Q. − *Not Q. − *Therefore, not P. − − All these proofs start with a proposition already verified or denied. − − This is the classic structure of circular reasoning, that is an abuse of the Law of the Syllogism: − − *If P, then Q. − *If Q, then R. − *If R, then P. − *P. − *Therefore, Q. − *Therefore, R. − *Therefore, P. − − Each of these three conditional statements would be valid by itself. Together, they create a flawed argument, because P now depends on itself to be true. The line of reasoning ends where it began, and is thus a circle. The only difference between this and ''proof by assertion'' is that the latter attempts to use a single conditional statement--"if P, then P"--while circular reasoning uses at least two, and typically three or more, syllogisms. − − Circular arguments can be very difficult to detect. Circular arguments found in the professional literature, or in [[propaganda]], typically use five or six (or more) syllogisms. − − Every logical system ''must'' begin with a set of generally accepted assumptions called ''postulates'' or ''axioms'' (from the [[Greek]] '''αξιος''' or ''axios'' worthy or deserving). Similarly, any set of definitions must start with a set of fundamental terms that need no definition. An axiom is usually a fundamental property of nature upon which all agree. Persons attempting to show that something is a fundamental property of nature when it is not, or a value of that property that is contrary to fact, typically use circular reasoning to make such an attempt. − − == Reference == − <table style="border:1px solid #AAAAAA; background: #EDF1F1; float:right; width:100px; margin-left:15px;"> − <tr><td>{{fallacy|circular reasoning}} − <tr><td>Use the <nowiki>{{fallacy|circular reasoning}}</nowiki> template to insert this warning on a page containing an example of ''[[circular reasoning]]''. The warning label will then link back to this page. − </table> − − * [http://creationwiki.org/Circular_reasoning Circular reasoning] by [[CreationWiki]] − − [[Category:Logical fallacy]]
Replacing page with 'Allahu Akbar'
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