The abhidharma texts of the Sanskrit Tripitaka of the Sarvastivada tradition as well as the Mahayana sutras present many of the main features of karma later elaborated upon in the treatises of the Vaibhashika and Madhyamaka schools. These features include the presentation of the karma – or more precisely, the karmic impulses – involved with actions of the mind as being the compelling mental factor of the urge (sems-pa, Skt. cetanā) that brings on and drives the action. It describes the karmic impulses involved with actions of body and speech as being compulsive forms of physical phenomena – namely, the revealing forms (rnam-par rig-byed-kyi gzugs, Skt. vijñaptirūpa) and nonrevealing forms (rnam-par rig-byed ma-yin-pa’i gzugs, Skt. avijñaptirūpa) of the body and speech. These compulsive forms of body and speech are the methods implemented for causing the actions of body and speech to occur. The Sarvastivada sutras present karmic impulses exclusively as the mental factor of an urge and are the sources for the Sautrantika and Chittamatra assertions about karma.