The concept of karma may have been of minor importance in early Buddhism. Schmithausen has questioned whether karma already played a role in the theory of rebirth of earliest Buddhism, noting that "the karma doctrine may have been incidental to early Buddhist soteriology." Langer notes that originally karma may have been only one of several concepts connected with rebirth. Tillman Vetter notes that in early Buddhism rebirth is ascribed to craving or ignorance. Buswell too notes that "Early Buddhism does not identify bodily and mental motion, but desire (or thirst,
trsna), as the cause of karmic consequences." Matthews notes that there is no cohesive presentation of karma in the Sutta Pitaka, which may mean that the doctrine was incidental to the main perspective of early Buddhist soteriology. According to Vetter, the "Buddha at first sought, and realized,
"the deathless" (
amata/amrta), which is concerned with the here and now. Only after this realization did he become acquainted with the doctrine of rebirth." Bronkhorst disagrees, and concludes that the Buddha "introduced a concept of karma that differed considerably from the commonly held views of his time." According to Bronkhorst, not physical and mental activities as such were seen as responsible for rebirth, but intentions and desire. The doctrine of karma may have been especially important for common people, for whom it was more important to cope with life's immediate demands, such as the problems of pain, injustice, and death. The doctrine of karma met these exigencies, and in time it became an important soteriological aim in its own right. ==The Three Knowledges==