The Seventeen-Article Constitution, which the Nihon Shoki dates to 604 and credits to Prince Shōtoku, ends with this rule: Sore koto wa hitori sadamu bekarazu. Kanarazu shū to agetsurau beshi. Matters should not be decided by one person alone. They must always be discussed with others.
Its first article opens with a related idea. Harmony is to be valued, and avoiding opposition is to be the principle. Other early sources date the text to 602 or 605.