Circular reasoning

Circular reasoning is an attempt to support a statement by simply repeating the statement in different or stronger terms. In this fallacy, the reason given is nothing more than a restatement of the conclusion that poses as the reason for the conclusion. To say, “You should exercise because it’s good for you” is really saying, “You should exercise because you should exercise.”

It shares much with the false authority fallacy because we accept these statements based solely on the fact that someone else claims it to be so. Often, we feel we can trust another person so much that we often accept his claims without testing the logic. This is called blind trust, and it is very dangerous. We might as well just talk in circles.


EXAMPLE 1

A confused student argues: “You can’t give me a C. I’m an A student!”

Circular reasoning is problematic because the claim is made on grounds that cannot be accepted as true — because those very grounds are in dispute. How can a student claim to be an A student when he just earned a C?

To clarify, no one is an “A student” by definition. Grades are earned in every class and are derived from a variety of different methods. The requirements in one class are set by the school and the instructor, so the same class taught by a different teacher or in a different location should yield two very different results (final grades). Merely claiming to be an A student does not make the claim valid.

NOTE: The false authority fallacy also applies here — you cannot use yourself as your own authority with total certainty. A doctor is more qualified to diagnose your shoulder pain than you are; your teachers are better qualified to evaluate your performance than a student.


EXAMPLE 2

A satisfied citizen says: “Richardson is the most successful mayor the town has ever had because he's the best mayor of our history.”

The second part of this sentence offers no evidence — it simply repeats the claim that was already presented. Don’t be fooled into believing that using the word “because” in an argument automatically provides a valid reason. Be sure to provide clear evidence to support your claims, not a version of the premise (the initial statement in an argument).


EXAMPLE 3

An obvious non-smoker blurts: “Can a person quit smoking? Of course — as long as he has sufficient willpower and really wants to quit.”

This statement contains a more subconscious version of circular reasoning. The intended argument simply repeats itself, disguised as a logical statement. The warrant is simple: “A person can quit because he can.” True, any smoker can quit, but the task is not as obvious or as easy to accomplish as the statement suggests. The arguer must provide reasons to suggest how a person can overcome an addiction, not to simply identify the obvious use of will power. This example also falls into distortion and the only reason fallacies.




SOURCE: http://ksuweb.kennesaw.edu/~shagin/logfal-pbc-circular.htm