Begs the question is a phrase commonly used in philosophical and logical contexts to indicate that an argument or statement assumes the truth of the very thing it is trying to prove. This is often referred to as circular reasoning or a logical fallacy.
For example, if someone argues that “God exists because the Bible says so, and the Bible is true because it is the word of God,” this would be considered begging the question. The argument relies on the truth of the Bible to prove the existence of God, but the truth of the Bible is itself dependent on the existence of God.