From 《
孟子·
离娄上》:
不以规矩,
不能成方圆 — 'Without the compass and square, one cannot form a circle or square.'
规 is the compass,
矩 is the carpenter's square — the tools that gave Chinese its very word for 'rule' (
规矩). Mencius was arguing that moral rulers need the rites as their tools.