For interactions between adults, the only important rule is that
taking anything from another person without their consent is
prohibited except by order of a court on finding that the taking is
necessary either as compensation for a taking which the other person
has done or in fulfilment of a contract which the other person freely
entered into.
There are no other moral imperatives for relationships between
adults.
There are of course other issues where it is not important *what*
behavior is accepted, but it is important that a small group of
acceptable behaviors be defined and everyone behave appropriately.
For example, it really doesn't matter whether you drive on the left
side of the road, or the right -- so long as everybody else in the
area drives on the same side.
And the responsibility of a parent to his/her child, and
relationships involving children, are a more complex area.
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