arbiter of truth
Who decides what the truth is?
In liberal mythology, various factions and individuals are constantly making arguments and propositional claims about what is true. This dynamic "marketplace of ideas" is presented as the powerful engine that has propelled liberal democratic societies to global dominance. This myth turns out to work fairly well, on condition that everyone participating in society believes it to be true.
In most times and in most places throughout history, such a myth would seem utterly preposterous. The question of truth was settled by whoever was most capable of imposing their vision by force. This meant, for most people, a constant state of fear of violent death at the hands of people who believed fervently in nonsense.
When people who loudly proclaim that they believe in nothing come to rule the world, it is by virtue of their nihilism that they arrive at their hegemony. However, the victory is always pyrrhic; to lead a people is synonymous with presenting them with a vision in which they can believe, a claim to the truth that can inspire, motivate, and uplift. Without a vision, without a moral claim to truth, a leader is always corrupted by his own lust for power, at which point his rule descends into tyranny.
To make a claim to power is, at its root, a claim on truth. They are one and the same. To proclaim that there is no such thing as truth is to stand naked among the crowds and say, "I am the captain now." Only doing so without an accompanying truth claim undermines your legitimacy, breeds resentment, and ultimately will bring about your ruin.