Negative - Do No Harm
Positive - Noblesse Oblige (If you are strong, help the weak. If you are beautiful, help the ugly. If you are rich, help the poor. If you are integrated, help the disenfranchised. etc.)
The beauty of these simple maxims, besides their simplicity, is that every person can find their own answer for how to apply these rules and they will produce generally positive results regardless.