A VIEWPOINT OF ETHICS
There are various approaches on ethics and ethical conduct. It is a favorite subject of philosophy and religion, with the first one trying to define it and the second one trying to enforce it. It relates to survival, as lack of ethics leads to death, eventually, be it the death of an individual or a nation or a whole planet.
Hurting other beings, whether people or animals or the earth itself cannot be without consequences on oneself. But the cause of the consequences can be obscure to some people.
Some people think God punishes the wrongdoer. Some think it is the universe. Some think life punishes the wrongdoer, since the repercussions of his actions are eventually directed against him. Some think that we are the only ones able to hurt ourselves. And when we feel we did wrong, we cause our "punishment", even though we only have a vague idea of where this condemnation comes from.
All the above are reasonable approaches. You don't hurt others so that you don't get hurt yourself. That's a valid foundation for ethics. And it is obvious to everyone that stealing or murdering, for example, entails the danger of going to jail. Or going to hell, if you are religious.
And then we have those who think they will get away with it. Such people normally believe that our life is limited to the life of our body. If you are just a accumulation of molecules, with a lifespan of 80-90 years, what's the point of being ethical? So they try to "make the most" out of their short lives, by treating themselves as the only important part of the equation. This is the lowest level of awareness for the civilized modern man. The "unit" approach. Unfortunately, due to their fixation on material acquisitions but mostly due to the fact that their lack of morality makes them puppets in the hands of those who want to control humanity, such people often manage to climb to the highest positions of society and hurt others on a massive scale.
But there are some people who will never hurt another, not because of fear, not because of abiding to a moral code, but simply because this is how they feel. They feel pain when others are in pain, so they naturally try to help. They will be kind to everyone, they will help the needy, they will take a wounded animal to the vet. Not because they want to make a good impression to God, but because they are sensitive to other beings' feelings.
This type of ethics is not guided or enforced. It is a natural sense of ethics, stemming from higher awareness. More and more people come to realize today that we are all somehow connected, that we are all part of a greater whole. When one gets hurt, the whole gets hurt to some degree. In that sense, there's no such a thing as pure altruism. Making others happy gives happiness to the being who feels connected to all other beings.
It appears, then, that moral codes exist because people do not realize that they are part of the whole. They do not realize that hurting another is like hurting themselves. Therefore, they have to be told "Love thy neighbor as thyself", until they get to the point of realizing that they are their neighbor.