J'aimerais bien que quelqu'un me corrige les fautes de syntaxe, grammaire... Merci beaucoup d'avance !
Voici mon texte :

I am going to talk about the notion of myths and heroes.
First of all, I would like to give a quick definition of that notion. Briefly, a myth can be defined as a story about gods or heroes, it can be a popular belief or a tradition or a false notion. Then, a hero is a person admired for his achievements, noble qualities and great courage. Moreover, they can be fictional like Superman, Batman, or real.
To speak about this notion, I've chosen to speak of the place of hero in society. In my argumentation, I'll try to answer the question : “Why does a society create myths and heroes ?”.
First I'll try to say heroes allow us to dream, then we'll see they are a model of achievement for society.

I) To begin with, the heroes used to dream through the myths they represent.
1. From a first point, they offer a dream world " quotation marks " with a different world where the laws of nature and man are not the same as on Earth.
To illustrate this point , we have Peter Pan , for example , the novel by James Matthew Barrie, the story tells the myth of eternal youth and offers a world without rules without parents makes children and gives them wings dream. Or even in the Harry Potter novel by JK Rowling, where magic is part of our world where love beats the darkness.
These fictional hero in a fictional world tell myths that human can not reach , it is an unreal perfection and this is the second point of this part .

2. If a second point , it is clear that mainly fictitious myths shows an unreal perfection. These are the best of all worlds that man would reach , knowing that it is still impossible to " mere human ." This can be seen , especially in the stories aimed primarily girls, who put forward the cult of beauty, like Sleeping Beauty , Cinderella ...

3. On a third point , the heroes that make us all dream , also allow us to imagine with a personality and a different life. To illustrate this idea, we have the Fantastic 4 movie, by Stan Lee and Jack Kirby, with super powers, physical and very different personalities. This myth superhero allows any type of personality to identify themselves or otherwise to create a world quite different.

Each of the stories I have cited here expose a dream world from different angles, they are suitable for both children and adults. Therefore, they affect all of society with ideas more or less direct according to the category of persons referred.

II) Thereafter, the hero has a role model for humans.
We can see that we project on the known personalities, this image of the hero.
Although we make dreams almost half of our lives we live in the real world. This is why the man is, to some extent realistic, and projects the power of fictional characters on a real person, for these acts. The man hopes, therefore, also be able to heroic deeds.

1. First, the man tries to reach the same perfection as his model. Since birth, mirror neurons affect our actions, we imitate what we see without necessarily realizing it, as a result, we need people to guide us towards perfection. I will take as an example, Martin Luther King, I saw the biography. This man is a hero because he was able to affirm his ideas face many opponents, he defended black men to have respect and peace in his country. He made ​​the courageous acts, heroic, on either its boycotts and speeches. He is a hero and someone to imitate and follow, especially for black men (as Nelson Mandela).

2. Finally, secondly, having models, influences society to make the best, which seems good. For example, during the attack of September 11, firefighters who were there are now considered as heroes. If we make the link with the fictional heroes I mentioned before, we will be able to compare these firefighters Fantastic Four for example. They have shown great courage, strength and impressive patriotism.

In conclusion, society create myths and heroes to dream the best of the world, imagine perfection. And thereafter, it throws these fictional heroes in real life to have models and progress in the right direction. I think the heroes are a good way to set goals in life, to have an example to follow when we are lost. The desire of the unreal, dreams can also be a good point but be aware the difference between reality and fiction.