Ethical Egoism -- we ought to treat others the way we want to be treated to ensure our own safety and prosperity.
At first glance, this sounds like the Golden rule--so called because it is found in a variety of religions and is generally accepted as an excellent guide to human conduct by a variety of cultures.
Unfortunately this golden rule is not so clearly applied by the ethical egoists. Their contention is that the only time to do something nice for someone is when you can reasonably expect reciprocity. For example, you might loan money to a friend in trouble, but only because you expect him to do the same for you at some future date. They insist it would be wrong to help someone from whom you could not reasonably expect an eventual act of reciprocity. The current concept of paying it forward is nonsense in their view. Even if someone did eventually repay the favor, and there's no evidence that they will, it will not directly benefit you; therefore it should not be done.
Many ethical egoists go so far as to declare that it is only moral to do things which directly benefit you. All other actions are defined as immoral. Others are willing to concede that it might be moral to act in a way that does not directly benefit you, sometimes.
This position differs from psychological egoism in that psychological egoism says that we are essentially biochemical robots that can only act in our own self-interest. Ethical egoism says that we do have a choice, but the only moral choice is to do things that benefit ourselves, or at least which do not result in a sacrifice of our self interest. The difference between the two is that psychological egoism is compulsive, while ethical egoism is a moral choice. Sounds like a Biology difference! Faculative versus obligate. If you are a faculative biped you can walk on two legs. If you are obligate biped you must walk on two legs. It's all about anatomy. In this case, brain anatomy.
My first objection to this position is familiar, we are social animals. We support each other because we have evolved to do so.
Furthermore, when philosophers ignore this, they ignore reality. No position based on a fantasy can be anything but a delusion. It is not a rational position, because it is not rational to ignore reality.
In other words, psychological egoism is a belief system. Since it is not based on facts, but rather what a person believes emotionally, there is no way to refute it or to prove it. If you believe it, you believe it and if you don't, you don't. This is the same basic position taken by many people of faith. If you believe, you need no proof. If you need proof, you will not be able to believe.