In a sense, yes. One must agree before you can start to disagree.
You must agree to:
1) The topic you guys are talking about. Two different topics discussed at the same time can lead to problems
2) The Facts: The facts are key in a discussion, and are generally used in debates and arguments. Each person must agree that what is stated is a fact.
3) You'll have to agree that there is a problem, and that a solution can be found. You are only disagreeing on how to get the solution.
hope this helps