I am a democrat because I believe that no man or group of men is good enough to be trusted with uncontrolled power over others. And the higher the pretensions of such power, the more dangerous I think it both the rulers and to the subjects. Hence Theocracy is the worst of all governments. If we must have a tyrant a robber baron is far better than an inquisitor. The baron's cruelty may sometimes sleep, his cupidity at some point be sated; and since he dimly knows he is doing wrong he may possibly repent. But the inquisitor who mistakes his own cruelty and lust of power and fear for the voice of Heaven will torment us infinitely because he torments us with the approval of his conscience and his better impulses appear to him as temptations.

And since Theocracy is the worst, the nearer any government approaches to Theocracy the worse it will be. A metaphysic, held by the rulers with the force of a religion, is a bad sign. It forbids them, like the inquisitor, to admit any grain of truth or good in their opponents, it abrogates the ordinary rules of morality, and it gives a seemingly high, super-personal sanction to all the very ordinary human passions by which, like other men, the rulers will frequently be actuated. In a word, it forbids wholesome doubt. A political programme can never in reality be more than probably right. We never know all the facts about the present and we can only guess the future. To attach to a party programme — whose highest real claim is to reasonable prudence — the sort of assent which we should reserve for demonstrable theorems, is a kind of intoxication.

--C.S. Lewis, 1946
"A Reply to Professor Haldane" in "Of Other Worlds: Essays and Stories"