At the request of numerous students who had received benefits from him, the Venerable Mahasi Sayadaw wrote a treatise in two volumes on insight or vipassana meditation. This small book from the Buddhist Publication Society contains the first volume of that work, in which Ven. Mahasi Sayadaw describes the seven stages of purification that occur on the path of insight. Unlike the second volume, whose English translation is titled Practical Insight Meditation, this first volume is not intended for beginners. From the translator's forward: "The foremost concern in this work is with a stage where, after diligent preliminary practice, the insight knowledges have begun to emerge, leading up to the highest crest of spiritual achievement, Arahantship."