Semde (Tibetan: སེམས་སྡེ, Wylie: sems sde; Sanskrit: cittavarga, "mind division", "mind class" or "mind series" is the name of one of three scriptural and lineage divisions within the Dzogchen (Great Perfection) tradition.[1] The Nyingma school of Tibetan Buddhism traditionally classifies its Dzogchen teaching into three main divisions: Semde, Longdé (Space Series) and Menngagde (Secret Instruction Series).[2]
Semde texts are mostly said to be translations by figures of the early transmission (7th–9th centuries) of Buddhism to Tibet like Śrī Siṅgha, Vairotsana and Vimalamitra.[3] These texts emphasize the "awakened mind" (Tibetan: byang-chub-kyi sems, Skt. bodhicitta), which is the true nature of the mind and is essentially pure and perfect, just like Buddhahood.[4] Semde texts critique tantric practice as being based on effort, and instead promote simple and effortless contemplation of the mind and its emptiness, luminosity, purity and inherent gnosis.[3][5]