Having intellectual arguments and debating are very important for self improvement where you improve how you express yourself , know how you feel and your real opinion towards things that you didn’t think about. You know how to negotiate, here you are talking with someone that always want the last word. Leave him say the last word but try to win the argument or finish your argument before he does that. For example, we can agree to disagree and I hope that my point of view would be beneficial for you.