They are ALWAYS subjective. Some people are unaware and try to keep those rules in place and the same rules, no matter what. It just cannot ever work for every situation.
Imagine trying to behave the same way and stick to the same script no matter what. You would not last one day. No one would.
Even Hitler. Especially Hitler. Impulse control was not his forte'.
When two or more people live in the same area they have to adopt some rules about who does what to whom. Any such rule is called a more', French accented e pronounced "mor-ay". The adjective form is moral, and the habit of following more's is morality. More's are arbitrary: they do not have to be right, only accepted. Another group on the other side of the river might have very different more's.
Ethics is acting honestly. People have differing ideas of what is honest and what is not.
Everybody behaves according to an invisible list of rules which they use to decide if something is right or wrong. Even people who claim not to believe in any religion have such an invisible list which they follow religiously. And because the lists are invisible, it is difficult to compare them, and that is why people want to establish governments to force each other to obey the lists of right and wrong. And then they get butthurt because the officials change the lists to their own benefit.
But the people solemnly tell each other there is no other way to do it. Then privately they do things some other way to conform to their own list of right and wrong.
This is why all civilizations eventually collapse.
Randy D 