This is a text I had to write for school. It became pretty good, so I'm sharing it with you NG people. It's my opinion about the Good and Evil ideas. I don't want to start a discussion topic, even because there are already some of then about it on the BBS, I just want to show my opinion and know what you guys think about it. So fell free to comment.

The Concepts of Morality
The humanity has always been concerned about the ideas of good and evil. What makes one good or evil? Why people choose one of these paths? And other questions like these ones. But the only question that really matters between them all is this one: What exactly are the good and the evil? Despite any ideological points of view, the answer to this doubt can only be reached with an examination on the human past. And for this reason, the following lines were written.
As people may know and the science have already confirmed, humans are no more than animals, and every animal chases to survive more than anything. As a consequence of this singularity, every action taken by men has always the inner purpose of survival.
To live in the collective group that formed our society, some human beings discovered that their actions that were always directed to theirs own survival, could also be directed for the survival of the others, resulting in benefits for the entirely society. This is what would be called "good" in the future, while the ones whose actions were still directed only to it's own survival would be called "evil".
As a matter of fact, the evil can be related to selfishness, since the evil actions are the ones that don't have the intention to help the others; while the good can be related to the collective survival intuition, since this is the cause and the effect of the so called good acts.
Although this is the basis of the origin and definition of good and evil, there is still two more factors to include, being one of them the environment influence. As we grow up, we see the actions of the people around us and interpret them as the way we should act too (mainly on the childhood). People who were rose in an ambient full of bad actions taking place tend to become bad, and the same thing for the good.
The other factor to talk about is the conscience. Many people see the conscience as the part of us that helps us to do good things. It's actually, the expression of the collective survival intuition that all of us have. That's why there are no entirely bad people. There are no entirely good people either, because we also look for our own survival as well. It's impossible to live without one of these two inner wills, but it's impossible to reach a balance between both of them too.
By getting all of the information together, we can see that every point of good and evil is actually linked to our characteristics as animals in someway. Therefore, the good and evil only exists by the actions we cannot control, the ones that are in the deepest corners of our minds and are just the same of all the animals, with the only difference that it's more developed. In the end, good and evil are just names that people created to differ the two kinds of human actions.