This arbiter needn't be something external. It's more plausible to cultivate an internal arbiter: ourselves. We already have an adjective to describe this arbitrating behavior: humility. It's something increasing difficult to cultivate these days when education and society becomes increasingly individualistic. People nowadays don't know when to stay silent in certain topics they know little to nothing about, and we've somehow taught everyone that their ideas are precious little snowflakes. The simple solution has always been "slow down, think twice, then act." It still is a solution. I don't know what happened to it.