For people to be good they must have exist a difference in them and this differences at time can cause a disagreement.
For the fact they are made up of the difference status, they Will exist a disagreement and will also device a solution in settlement of conflicts.
Human being disagree to agree, they said things which they know and which they believe to be the truth but that truth may seem untrue to another person since we are from difference background, values and culture, and the degree of the differences and beliefs will still exists which will still enact disagreement.
Disagreement can erupt in many ways, it can be in the form of material things, it can be in the form of financial and it can also be in the form of reasoning.
Man strive for survival, at times they differences they had isn't all about money but they disagree to get more understanding of their life's.
I could clearly remember once, when my sister told me that she can solve mathematics more than i do.
I told her no that she can not performed more than me, then, i went ahead to say that i am the best, she couldn't bear it, to her it was a challenge and a kind of slap to her face.
That alone lead to an argument but at the end, i was defeated because i was no match for her.
That is what argument can do at times, it will bring out the truth in some occasions.
And the best of you will be reveal.