"Contrast this way of thinking about actions to ancient times. People do not think like we do today."

That's wrong. People thought exactly exactly the same way we think today, and they were just as intelligent. They just knew different things. If you took an infant from the Ming Dynasty in the 15th Century, and magically raised it in modern China, it would be just like everyone else in modern China. Ancient people were self interested, just everyone today, and that interest extended to the other people that mattered to them. That can't be changed since it is inherent in every human being from the time we are born until we die. Once you accept the reality the everyone is looking out for #1, all ideologies are bullshit that are being used to manipulate other people to fulfill someone else's self interests.