A lot of people have the view that humans are terrible creatures who are evil and only care about themselves. I can certainly understand why these people think this about other people, I used to have such a view myself just two years ago. This is completely wrong, and I will demonstrate it below.
There is going to one guy who is going to tell me, "you never defined what evil means". I just know someone would come along sooner or later and tell me that. In that case let me explain what "evil" means. It means exactly what you think it means. "Good" is being loving, helpful, concerned, so forth, and "bad" is the opposite, stealing, lying, cheating, and so forth. I do not use the word "holy" because of its religious connections so I may interchange "virtue" or "just" for "good", and interchange "evil" or "vile" for "bad". The understanding of the usage of good and evil is something which is very straightforward over here.
I also want to say one more thing before I start discussing human nature. I have no problem with pessimism. In general I look at the world in a pessimistic way. That probably has something to do with the fact that I am a nihilist. I despise optimism, as Voltaire said, "Optimism is the madness of insisting that all is well when we are miserable". Therefore, I would have no problem whatsoever agreeing to that humans are terrible evil creatures. But I cannot bring myself to such a view because it is just wrong.
Sing to me, Muse, Astraea holds the scales of judgement. Let one side be dominated by evil and the other side be dominated by goodness. Angels outweigh the scales completely to the good and demons outweigh the scales completely to the bad. If an average human is placed on the scales, he shall not reside with the angels nor with the demons, the scales shall not dominate one side. The human is not entirely evil nor entirely just. But the scales of judgement shall be in favor of justice. The mortal shall not go to the valley of Hades.
This is what people are, we are mostly good, not completely good. Indeed, our history books are soaked in a lot of blood. However, the problem is that we look at the bad things that happen and overlook all the good things that have happened. That is actually part of human nature, to look at the bad and oversee the good. But we need to look at the both the good things people do and the bad things people do then it is no doubt that the good things outweigh the bad things. I will give a very simple example. I live in New York City. Every day, or almost every day, I hear in the news about how some person murdered or shot another person. That certainly is a bad thing, and some people would get the impression from this frequent list of murders that people are terrible. The problem is that we need to compare these bad people to the good people in New York City. The fallacy that many people commit is that they only look at the bad. What we need is to look at both and compare one against another. One person may have been killed yesterday but compare that now to how many people not-killed yesterday. There are about 11 million people, so we have one murder, and millions of non-murders approximately each day in New York City. It is a huge fallacy to look at numbers like that and make the statement "humans are murderous creatures". This is the first reason to why human beings lean mostly good on the scales. Thus, remember that when we make a statement about the virtues of humans we need to compare it against all people. I am not making the statement that we are angelic, because that would be wrong, neither are we on the side of being demonic, that would be an even bigger error, but we are on the side of being good.
There is an evolutionary reason for this. Human beings have been able to progress and develop over the many epochs precisely because humans were good. It is an evolutionary advantage to be good. A society which consists of good members is far more likely to survive than a society in which the members are bad. This is because good people are able to cooperate together and solve problems that way. A society without good members would be dysfunctional and a failure. Humans are the most empathetic and sharing animals. Humans will cooperate together if they have to share their rewards, other animals, like monkeys do not do the same. It is true that monkeys share but their sharing skills are not as evolved as that of a human. But at the same time people have self interest, they think about themselves first. Though I do not think that this is necessarily a bad thing. We should think about ourselves first. If we do not think about ourselves first then who will? We need to think about ourselves first otherwise we would have been dead as a species, it is a necessary evolutionary trait that we have self interest. I consider it to be fine to have self interest, I see nothing wrong with self interest, nothing to be embarrassed about, we just need to have concern for other people too and not just ourselves. Humans certainly evolved in that way, we mostly care for ourselves, but we also care for others, which is part of the reason why we are the most successful species on the planet.
This should be contrasted with the religious point of view. Religious people often think of people in a negative way. This is perhaps why two years ago, when I had some Jewish beliefs, I thought that about people. I thought that people were savage evil creatures that only destroy themselves. Why? I think it is because that is the way religion looks at people, especially Christianity. That we are sinful and we should be ashamed before God who is the ultimate source of good. The religious view is that we act good not because we are good by nature but because God told us so. This frightens me very much. I have heard numerous times at this point religious people telling me that that without God they would not know good from bad. Without the Torah (or the Bible, or whatever) they would not know not to kill. I even ask a question to them, "if there was no God and there no Torah, you would be going around killing, stealing, pillaging, and raping people?". To my surprise many of them say "yes". How am I supposed to respect a person like that? How can I possibly respect a person who has just confessed to me that he does not see why killing, stealing, pillaging, and raping is wrong and furthermore admitted that he would do it if we can get away with it? I have many problems with religions, this is one of them. The way it devalues human life. This is why I am not so surprised that people like Pat Robertson can see what happened in Haiti as being the fault of the people because he does not put the same value on their life as a normal person would.
I have a similar problem with animal lovers that go too far. I have no problem with people who like animals, I like animals too, I have a dog and a cat. I am talking about the kind of people who value animals more than people. PETA, for example. I have heard this throughout my life, "look at the animal kingdom, look how great they are, if only people can be as good as the animals". No, animals are not good. Nor are they bad. They are neutral, they cannot be responsible for their actions. The human being has an intellect. This is what can enable him to be good or bad. People can use their intellect for terrible things, as we see in history, and for great things too. A human is capable of being worse than any animal. But in general, a (good) person is far superior and better than any animal. To think otherwise is complete stupidity and the same devaluing of human life that religions often do. Simply compare what a human does to what an animal does (of course, humans are animals too, but I am separating the human into a class all of its own here). Humans have worked to benefit animals, not for the sake of themselves but for the sake of animals, only because humans were empathetic and wanted to spread their goodness over to other creatures. If a human sees an animal starving in a forest, he may give his own food to the animal. I wonder how many animals would do that same to people. I understand that they are bad people who do abuse animals, I know that, but I am talking about a kind of person who is against animal abuse. Such a person is far superior than any animal in existence. Just listen to the stories of how a friendly person worked with animals his entire life and one day got killed by them. The point is that a good person is far superior than any animal. And a bad person is worse than an animal. This is because humans have intellect they have the capacity of doing good and bad. Animals are just neutral not responsible for their actions. But to say that animals are good and people are bad, as many radical animal lovers imply, is stupidity and the same devaluing of human life that I see in religion. This is why I am not surprised that you have animal groups like PETA put pictures of dead chicken in a slaughterhouse right next to pictures of Jews in the holocaust, because for them human life does not have so much value.
What I think is important is to teach people values. We are already good by nature. But we can be an even better species if we learn good values. I think humanistic and liberal values is what will make humans even better.