Main purpose of discussion is to exchange views and benefit from each other’s knowledge. Such exchange of knowledge is based on logic, generates thought process and promotes mutual respect and friendship, which in some cases become life-long. The participants usually end up more enlightened.
Argument is generally aimed at impressing others, prove one-self right and demean the other. This is the product of inflated ego, closed or narrow mindedness and the aim is not to prove what is right but to prove who is right. After the sensible arguments get exhausted, one starts feeling helpless but also wants to hide it. This results in argument for the sake of argument and show of anger, which is aimed at hiding the helplessness. Increase in anger creates a sort of anxiety. In such condition when the person does not find suitable words to express the intensity of his anger, he starts shouting and using foul language that clearly indicated his helplessness and mental condition. Use of indecent words provokes the other person, which results in bitterness and sometimes ends up in break in relations and might even create enmity.
At times people use foul language just to express their hatred and disapproval and use worst possible words for the opponents. Unfortunately, this has become quite common. Plenty of such examples can be seen on TV, social media websites and some discussion forums. Political and religious discussions, personal likes and dislikes about personalities and events are the most evident examples. It is worth remembering that shouting never convinces anyone, logic can.
Whatever be the situation, use of indecent language especially by the educated persons can never be taken as correct and is rather disapproved by serious minded persons. Remember that how and what a person speaks is reflection of his personality and mental level.