The Golden Rule (do unto others as you would have them do to you) and the Wiccan Rede (If no harm is done, do as you will).
I prefer the latter.
"Every atheist I have known has always fallen back upon the one concept echoed worldwide, and taught by religious and secular leaders throughout all time: the so-called "Golden Rule." Jesus was repeating an old Jewish proverb when he said "Do unto others as they do unto you," and Confucius was recording an old Chinese saying when he wrote "Do not do to others what you would not want done to you."
All atheist systems of morality seem to derive in various ways from this core principle, and so it would be appropriate to say that atheists stand for the Golden Rule in its fullest meaning and significance. I believe that any rule or belief which violates this principle is discarded by most atheists as immoral..."
Richard Carrier, 1999
and so crunchy and step:
I cant see were, anybody has broke the golden rule (do unto others as they do unto you).
Unfortunately, it is merely a goodwill gesture, and is not a practical belief to enforce. Because, for example, a violent warrior is going to have a very different idea of what normal conduct is. One who fights for survival is both willing to attack others, and defend himself, and upholding the ethic of reciprocity appears to tell him that it is ok for him to attack others, just because it's something he expects to happen to him too. Survivalists and those who expect others to treat them badly, who are happy in a tooth-for-tooth world are given the all-clear to go forth and act as they wish. The ethic of reciprocity is too idealistic, and can only ever maintain the status quo rather than create an atmosphere of goodwill. Most support it because they are unable to think of a better way, and it has a feel-good factor because the statement is "seen as good".