A 5th-century BCE philosopher argued you should love strangers like family

Where Confucius taught graded love, stronger for family and weaker for strangers, Mozi argued for jian ai, or 'impartial care': treating everyone's interests as equally important, since partiality toward your own is exactly what drives conflict between groups. Mohism became a major rival to Confucianism in ancient China, complete with its own logic and organized following. It's one of the earliest documented arguments for universalist ethics.

— Mozi, Mozi — Mozi, chapter on Universal Love, c. 5th century BCE