Samatha practices, which involve focussing the mind on a single object, are supposed to result in an ascend - ing series of four ‘material absorptions’ (or ‘trances’, rupa-jhana) and a further series of four (or five) ‘immaterial absorptions’ (arupa-jhana), that bestow upon the practitioner various supernatural powers. Vipassana, on the other hand, involves the disciplined contemplation of seminal Buddhist doctrines such as impermanence or nonself, and leads directly to nirvana or full liberation. Nirvana is achieved in four successive stages known as the ‘noble attainments’ (ariya-phala), the first of which is called sotapatti or ‘entry into the stream’. While samatha is an effective means to acquire specific spiritual powers, such as the ability to levitate or to read minds, only vipassana leads to enlightenment proper. Since the soteriological ramifications of samatha and vipassana