Nature (God) has given the mystic physical eyes, and he gladly uses them. It has also given him mental eyes (reason), yet he foolishly refuses to use them. The sharpening of reason and the development of practicality constitute valuable features of the general human evolution. Scientific observation and rational thought are necessities of a higher human life. Those mystics who do not believe this to be the case, who persist in maltreating their intuition and maiming their intellects, can be quickly discerned by their neurotic attitudes and exaggerated statements. They abound in every mystical movement, cult, and society. To get at the truth we must reject their partial one-sided and oversimple approach. To repudiate or denounce reason as being unspiritual and to disdain or discard balance as being unnecessary, to follow every upsurge of fancy and to accept every claimant as intuition--this may lead the mystic further along the path he has chosen, but it will also lead him nearer to the unfortunate necessity of requiring a psychiatrist's attention. Only an incorrect metaphysical approach could contemptuously pronounce intelligence to be an enemy of intuition, just as it always pronounces "spirit" to be eternally opposed to "matter."
-- Notebooks Category 16: The Sensitives > Chapter 2: Phases of Mystical Development > # 191