Every human being on the planet has opinions and every one of these opinions has a different reasoning for agreement or disagreement. This fundamental difference in the manner that people think is important for a myriad of reasons. The first of the reasons is that open discourse allows people to see things from another perspective, one that has had a different life from your own. The second is it allows you to either accept the ideas that the individual who you are having this discourse with and have a more informed and new opinion or it means that you must be able to respond to the individual who you are speaking with and present your information. The last reason is it allows you to spread your ideas to those who may not know them or in a way that others have not seen.
Before I further explain the importance of the statements above, I would like to say a few things in regards to how one should try and discuss. Firstly, come in with an open mind. You can not learn new things if you are not willing to consider the other side's point of view. Secondly, do not make personal attacks against the person during the debate. Not only would this be in bad form, but it also distracts from the debate itself and it does nothing but cause resentment between individuals. You can disagree while remaining civil. Lastly, if you and the other individual or individuals who you are debating with do not agree with your sentiment, agree to disagree. If your opinion does not change, that is fine. Open debate is used for teaching individuals new view points and potentially changing their view of the world. Open discourse is not an excuse to attempt to harm an individual or that individual's character, even if you disagree. A last note for after the debate, always try and present their argument in a positive light, even if there is disagreement. If you can not do this, tell people to go speak with the individual who made the original claim. Not only is there no better source for an individual's argument than the individual, but it also keeps you from presenting someone's argument in such a way that it changes the meaning.
Keeping an open mind to discussion is very important. If two people enter into a formal or informal debate with each other, then the two have willingly decided to attempt to present their views on a particular subject and their reasons why. If one side is open to the information that the other is presenting and the other is not, the discussion may often fail. The reasoning is simple. When two people are discussing something, often they have a conviction on the particular subject. Even if that conviction can be moved by the statement of new facts, the person may become angry when someone will not take their opinion into consideration. You often see children do this when their parents will not listen to their reasoning, but, in this case, it is often two intelligent people with an opinion on a subject. If one side adamantly refuses to look at the other objectively it creates a division that does not allow for an understanding and presentation of information, which should be the main reason for people to begin debates.
When you debate, you are presenting a view with the intention of spreading your information and reasoning. This reasoning was created from life experiences and the information that you have accumulated throughout your life. The problem with only having an opinion from your own experiences is very simple, your opinion is only based on your individual experiences and, as a result, it may not be the majority. A simple way to fix this is to talk to another individual about your opinion. This simple act allows you to either confirm your opinion farther by the individual agreeing or reevaluate your opinion by having another opinion presented (even if the individual's end result or opinion is the same, their reasoning may be different). This also works vice-versa where your opinion may change the mind of someone else.
Open discourse between people allows for individual debates where ideas change and flow and individuals teach each other. This allows new ideas to form and ideologies to change. Discourse is one of the fundamental reasons why humans are, in fact, humans. Our reasoning and ability to communicate allow us to form and present ideas and these things have shaped us into what we are today. Go talk to another individual, discuss new ideas, and formulate your own opinions. You could change someone's life, make new friends, or even learn some new information about yourself.