What's happening is that each year our old flat earth of conventional reason becomes less and less adequate to handle the experiences we have and this is creating widespread feelings of topsy-turviness. As a result we're getting more and more people in irrational areas of thought—occultism, mysticism, drug changes and the like—because they feel the inadequacy of classical reason to handle what they know are real experiences.
Ch. 14 - Zen and the Art of Motorcycle Maintenance (1974)