A set of rules does not equal a set of morals. Take any developed country in the world today, and while they all have laws, the laws do not define the morality of the populace. for example, here in the US, we have wars, abortion, gay marriage, global warming. These are all contentious issues, with people on both sides claiming the high moral ground. Both sides of each argument cannot be morally acceptable, as each claims the other is immoral. So which is correct? If the rule is created, and the law is passed, does that make one side morally correct?
Maybe it is the ultimate expression of understanding? To take the extreme example of alien and twisted: An alien race visits earth. They are intelligent, communicative, and females eat the males after insemination in a grotesque and agonizing manner. While, I may morally find this reprehensible in humans, who am I to condemn a whole race of creatures that have evolved in a way that seems wrong to me?
Good and evil are circumstantial. 2000 years ago, slavery was good. Today, it's bad. 200 years ago, women were second class citizens, and it was good. Today, that kind of thinking is bad, and you will get an earful for even mentioning it. 100 years ago, mentally handicapped children were locked up in basements or barns, as it was what you did with children who were obviously evil. Today, you'll go to prison for a very long time for trying that. In 500 years morals will have changed again due to what ever circumstances prevail at that time.
To really see moral relativity in action, try asking the following to various people:
Would you murder someone to save a thousand people?
Would you murder a really good person to save a thousand people?
Would you murder a really evil person to save a thousand people?
Would you murder someone with only a day to live to save a thousand people?
In my experience, only a few people will stick to their answer no matter what circumstance is presented, as long as the premise (kill x save y, y>x) remains the same. Most will be swayed by one factor or another.
Thank you.