(1) Yes, mystical experience must collaborate with rational thought. But there is a higher kind of mysticism, which prunes away the accidental and penetrates to the essential. (2) Intellectual knowledge is certainly relative. But what lies beyond it is for us ultimate truth. That there may be a truth beyond this in turn need not concern us at present, for nobody could either dispute it or demonstrate it. (3) The urge for higher knowledge is not an act of the ego but a prompting from the Overself. That it gets mixed, in its earlier phases, with egoistic desires is true but these slowly fall away.
-- Notebooks Category 7: The Intellect > Chapter 2: The Service of Intellect > # 61