The Lagoon TechMy little blog in Cyberspace.

What exactly is circular reasoning? Circular reasoning is when you attempt to make an argument by assuming what you are trying to prove is already true. In other words, instead of using A to prove B true, you are using B – itself – to prove B true. This is a bad way to argue.

Here is an example. Larry tells Mike about a new spray cleaner that will clean anything on any surface. Mike is intrigued and asks Larry how he knows the new cleaner will clean anything. Larry explains to Mike it will clean anything because it says so on the label.

Notice what happened? Larry used the bottle’s label to prove that the label is true. This is not a proper way to argue, since you are not proving anything. At best, you are showing you have faith the label is telling the truth.

This may be a surprise to you, but circular reasoning is not always a logical fallacy. There are arguments made with circular reasoning that are valid and can be applied without issue.

One example of a good circular argument is the following: “If we did not have laws of logic, we could not make any arguments. Since we all can make arguments, laws of logic must exist.”

This circular argument is valid. Laws of logic must be assumed to be true, otherwise no arguments could ever be made. If you were to argue the laws of logic do not exist, you would be using the “laws of logic” to claim that the laws of logic do not exist. That does not make any sense.

Summary: Circular reasoning is when you attempt to make an argument by assuming what you are trying to prove is already true. However, there are times when circular arguments are valid and make sense to use in a discussion.