Circular argument

From FreeThoughtPedia

Also known as Begging the Question, a circular argument is one that supposes the proposition (directly or indirectly) within a preceding premise. Or more explicitly, a circular argument makes a conclusion based on something that has already been presumed in the argument.

[edit] Example

"The study of physics is beneficial because good physics makes for useful analysis."

Here, we can see that the statement seems quite reasonable until we place it into a more explicit form:

"The study of physics is beneficial because physics makes for a beneficial study."

Where the argument is of the following form for assumption A,

Premise (1): A implies B

Premise (2): Suppose B

Conclusion: Therefore A

[edit] Examples that don't follow the circular argument fallacy

Person A: God doesn't exist.

Person B: Here is some historical evidence for the miracles of Jesus.

Person A: Miracles are impossible, therefore God doesn't exist.

Here, this argument doesn't follow the particular "A is B, thus A is B" format. Instead, it appeals more to the "Argument from Personal Incredulity", which attributes that because one personally finds a premise unlikely or absurd, the premise can be supposed to be untrue, or that another favoured but unproven premise is true instead.