Eliot is right it is called the Golden Rule (or Golden Law as it was called after the 17th century) but it is not attributed only to Confucius but appeared in the philosophies of ancient Babylon, Egypt, Persia, India, Greece, Judea and China. In Christianity it is has been attributed to Jesus. In Judaism the Great Commandment 'Love thy neighbour as yourself' is considered another version of the Golden Rule.

"Do unto others as you would have them do unto you" is how we usually say this phrase.

It is called the Golden Rule. It is attributed to Confucius, but he refers to it as the first and only rule of life. I guess every culture knew about it.