There exists a widely accepted opinion in Chan/Zen 禪 studies that Chan enlightenment is a mysterium ineffabile, impenetrable by human intellect. Reviewing the debate between Hu Shi 胡適 and D. T. Suzuki over Chan enlightenment and accounts of testimony by Chan masters and practitioners in history, this essay argues that Chan enlightenment can be understood rationally and intellectually. By analyzing the time-honored Chan practices that have led to enlightenment, it seeks to understand the mystery as an extraordinary mental condition in (...) which an enlightened person temporarily blocks thinking in terms of language, consciousness, and intellect, and experiences a momentary “erasing” of what has been impressed on the psyche since birth. (shrink)