In this dissertation I examine the definition of Buddhist 'lay brother' ( upasaka ) in ancient India. I mainly draw on canonical and post-canonical texts of philosophy and monastic discipline belonging to various Buddhist schools. Firstly, I show how some schools maintained that lay brothers should take all five precepts, others maintained that lay brothers should take one to five precepts, and others maintained that lay brothers should not be required to take any precepts. Secondly, I present and discuss evidence on those lay Buddhists who were not 'lay brothers' and who were not even eligible to reach such a status, e.g. butchers, kings, and eunuchs. The Buddhist clergy encouraged all these people to participate in the ritual of the weekly fast. Thirdly, I show how some Buddhists related to the Mahasam ghika school maintained that abortion, a grave infringement of the first precept, does not entail loss of upasaka or monastic status. Finally, I present an edition and translation of an Indian text on Buddhist lay persons extant in Tibetan, the Upasakasam varas[dotbelow]t[dotbelow]aka and its commentary, the Upasakasam varas[dotbelow]t[dotbelow]akavivaran[dotbelow]a, both written by Sunayasri.
