On the surface this might seem reasonable, but then if you need a rule to tell you whether to help someone in need then you already have a problem with your sense of humanity.
Would you say that the mark of a healthy and sane person is that she does not have any clearly stated rules in regard to her sense of humanity - but that she instead acts humanely without thinking of whether it is humane or not?
The do no harm version is essentially - live and let live - do not tell others what to do and do not judge them.
But what when others don't let you live and judge you?