Stop arguing in circles. You're begging the question.
•A: Why do two lines that are equidistant from one another never meet? B: Because they are parallel. A: You are begging the question.
2. to invite the (following) question. (This reinterpretation of beg the question is incorrect but is currently in widespread use.) •His complaints beg the question: Didn't he cause all of his problems himself ?