H. S. Lewis - Wisdom of the Sages - Thou shalt not be credulous
The second command of this decalogue is:
THOU SHALT NOT BE CREDULOUS!
Credulity is defined as "a weak or ignorant disregard of the nature or strength of the evidence upon which a belief is founded: in general, a disposition, arising from weakness or ignorance, to believe too readily, especially impossible or absurd things."
Wherein do doubt and credulity essentially differ? In doubting, do we not disregard offered evidence? do we not show a disposition to believe? do we not substitute one belief--often our own precious credulity--for that which someone else possesses?
The Mystic neither doubts, nor is he credulous. He demands proof and seeks it. He believes nothing, but either knows or does not know.