What is it?
Circular reasoning (also called begging the question) occurs when the conclusion of an argument is used as one of its premises. In other words, the argument assumes what it's trying to prove, creating a circle in reasoning.
Examples
Person A: 'The Bible is true because it's the word of God, and we know it's the word of God because the Bible says so.'
Person B: 'I'm the best candidate because I'm more qualified than anyone else.'
How to Avoid This
Make sure your premises can be independently verified and don't already assume the truth of your conclusion. Ask yourself if you're using evidence that doesn't already assume what you're trying to prove.
How to Counter This
Point out that the argument assumes what it's trying to prove. You might say, 'You're using your conclusion as evidence for itself. Can you provide independent evidence for your claim?'