Literally: (to) use – harmony – do – valued
Alternately: A statement that the most important thing is good relations between people. One should cherish positive interpersonal relations in all of society.
Notes: This one is in the “Seventeen-Article Constitution” (Japanese 十七条憲法, Juushichijou kenpou), a 1400-year-old treatise on good governance based on Buddhist and Confucian thinking. Some of my sources suggest that it was borrowed from the foundational Confucian text, the Book of Rites (Japanese 『礼記』 = Raiki).
This phrase can also be rendered in native-Japanese style as 和を用って貴しと為す (wa wo motte toutoshi to nasu).