There is a big difference between 'arguing' and 'debate'.
I believe that it is ok to disagree with someone up to the point that you become disagreeable. What I mean by this is that I think that Rhapsody and I could probably debate all day and we would still be friends at the end of the day(at least we wouldn't be mad at each other). It's just a debate.

People actually learn from debating. At least it makes you think about the topic that is being debated. It makes you try to analyze the topic. Whether you like it or not, if you get involved in a debate you will learn something. Even if it is from the person you are debating against.

It's when the debate becomes personal and argumentative, that the debate becomes an argument. That is where we need to draw the line. Just my thoughts.