I believe in this so much, for example, if you purchase an item you would not want this item stolen from you and so would not steal from your fellow man, this covers so much.
This rule encompasses some variation of nearly every act of kindness. It stems from empathy, from being aware that others feel what we feel. Empathy allows us to be humane. When we follow this rule we make another's life better. Our life then has value beyond our own existence.