The narrow mystic who sets up for others his personal limitations in mystical development, does a dangerous thing. His justifiable fear of barren, dry intellectualism may become exaggerated into a fear of wisely discriminating reason. This can end only in over-credulous accepting of superstition and disturbance of the mind's balance. It may even lead in weak intelligences to a mild insanity.
-- Notebooks Category 16: The Sensitives > Chapter 2: Phases of Mystical Development > # 212