‘The oldest account of the history of the Order after Buddha’s death is in the last two chapters of the Cullavagga of the Vinaya, which give the
‘Go forth, O Bhikkhus, on your wanderings, for the good of the Bahujana, for the happiness of the Bahujana, – in compassion for the world
Indeed, in the Vinaya Discipline, a member of the Sangha is defined as someone who has left the life of a householder and taken the all the monastic vows as decreed within the Vinaya Discipline. The breaking of these vows either attracts reforming behaviour, or expulsion from the order. However, the Vinaya Discipline also defines a ‘member of the Sangha’ as someone who has ‘realised emptiness’ irrespective as to whether they have renounced the lay-life.