An argument gives you the opportunity to
a. prove someone's incorrect statements
b. make someone feel better
c. change someone's point of view
d. show the weakness in someone's character

c. change someone's point of view

When you argue, what you are doing is trying to persuade someone to your way of thinking.  This is why you may have heard the terms argumentative and persuasive (with regard to papers/essays) used interchangeably.  Within this type of paper, what you will do is reason by way of presenting evidence in support of your point of view so that readers might, too, consider it.  

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