(Chinese: “Discussions of Essentials”), treatise by Hsieh Ling-yun, an early Chinese Buddhist intellectual, valued chiefly as one of the few sources of information about the author's eminent teacher, Tao-sheng (Tao Sheng) (d. 434). According to Tao-sheng, enlightenment is a sudden and all-encompassing experience, rather than a gradual process as described by his contemporaries. This assertion, firmly grounded in the Prajña teaching of the undividedness of truth, generated widespread intellectual debate in China.