It was Friedrich Nietzsche who once said that everything that is good was once upon a time considered evil. In some way I agree with that statement and in another I do not, but I understand what he meant to the point of using Nietzsche's idea as inspiration for the following write-up.
When I say I agree with his statement I mean that there are certain things in life which we hold good because we think they are sacred, or that they would necessarily improve our happiness, or that the good thing is simply analogous to common sense or acting out of the supreme confidence of intelligence. Or that the good thing or way of seeing something will help us along our (ultimate) objectives. However, since no one will ever know everything and escape being stupid to some measure we must resign ourselves to the fact that whatever we believe is good for us is a result of the faith we have that it is so.
Everything that does not fall within the ambit of us making a good moral judgement thereon we see as being necessarily evil since this is the way our minds work. It might be that the sorting of a thing into possibilities which the limits of our intelligence impose upon is dangerous. ie. The problem of whether a thing is good or evil may simply not apply, it is of such small consequence that it is really pointless bothering about such an expensive moral principle (closely related to the idea of thinking too much). To see things in black and white is a dangerous tendency. It may be that we see a thing as being evil because we do not understand it, or display a lack of thinking prior to casting a hasty moral judgement or as the case usually is: we act out of stupidity or ignorance.
When I say I do not agree with Nietzsche's idea we inch closer to the idea of what human nature is. When we attempt to express our idea of ourselves we set up artificial limits beyond which we refuse to consider what we are capable of. For the person who believes in the traditional sense of the word good, this might mean that he describes himself as one who would never ever lie or commit murder or sleep late on a school night. And when such a person comes across what he sees as something which his value system describes with the label evil he becomes shocked, and says to himself that that is not what human nature is. That the action he sees before him is an aberration of what is normal. See cultural relativism or the problem of what to do on a rainy Sunday afternoon.
It is important to note here the distinction between the actions of a person and the person himself because this consideration has important implications for the concept of punishment and reward. We must consider whether the person had enough free will to exercise in such a way that he could control the outcome of the event he either started, got caught up in, or is being blamed for. The more will to power it takes someone to cause something to happen the more we can say that that person is responsible for his actions. Because as you know, accidents happen and people make mistakes. We should apportion whatever judgement we have about a person by looking at how much that person was/is really responsible for his actions.
However, the question of what human nature really is begs us to ask the following question. If I knew something to be evil, if I knew that the action I was about to commit was really and truly evil, then would I go ahead and commit it? That really depends on what you're about to do and what you want to ultimately achieve. And it's important to see that casting a judgement has a lot to do with what you're about to do. The context of your judgment must be taken into account. As though what you're about to is in some way connected to how you will judge your action. It is really pointless to think too far ahead and predict and prepare for every little combination of possibilities which might come your way. That is the same thing as thinking too much. Usually this leads to the concept of utilitarianism which tries to answer the problem of good and evil with try to find what is ultimately in the best interests of as many people as possible.
Let's explain by way of an example. A man threatens my life, he is armed with a loaded gun and I have reasonable intelligence at my disposal to believe that he will in fact shoot with the expressed intention to kill me and that attempting to negotiate or just walking away from the situation, is impossible to do. I have a loaded gun pointed at him too. This is a classic it's either you or me-situation. While it's against my idea of being good, or what is human nature, to kill the man I have to ask myself if the lesser of two evils is that I should allow myself to be killed in favour of a higher (self-defeating) moral principle or should I exercise my instinct to self-preservation and do the right thing.
Long long ago it might have been considered evil to believe that the earth was anything but flat, in fact some principled people killed some un-principled people who were brave enough to believe otherwise. If you study history carefully you will find many examples of this kind of thinking.
To really know what is good, what the essence of being good is we must try and find what it is that has never, never ever, changed in the whole intimate history of humanity or even in our own short personal histories. For that thing, is the ultimate good. And as you study the changing perceptions you have about that history you will find that your idea of the ultimate good is not static or objective, that it subject to change and has always been quietly changing - sort of like the way a bird's beak chips a mountain down in the classic explanation of infinity (only much faster). So you see, trying to look for good as a thing is really pointless. You age, your intelligence increases, you become more wise, things that affect you happen, you see more (or less) of the world and your whole worldview consequently changes. This says alot about the concept of free will, and the idea of believing in a god(s) represented as an unchanging idol(s). This is probably why some religions, such as Islam, Judaism, certain sects of Christianity forbid the representation of God in any worldy form. Although that assertion is open to interpretation.
I guess it all boils down to whatever you think and decide as long you are willing to take responsibility for what you do. Me? I use The Golden Rule. I treat other people in the way I would like to be treated.
I started this write-up by saying that Nietzsche observed that everything that is good started out as evil. I'll end off by admitting that I wonder about the things we think are good, that are in fact evil and should have stayed so.