Inspite of the numerous comments and criticisms which are associated with the founding of the Order of Bhikkhunis it is clearly evident that it soon became a recognised component of the religious organization of the Buddha.
Bhikkhu ca sīlasampanno bhikkhunī ca bahussutā
upāsako ca yo saddho yā ca saddhā upāsikā
ete kho saṅghaṃ sobhenti ete hi saṅghasobhanā.
Virtuous monks and learned nuns,
Laymen and laywomen of great devotion.
These indeed are an ornament to the Saṅgha.
They do indeed adorn the Saṅgha.
The catuparisāor the fourfold assembly, which included both Bhikkhus and Bhikkhunis together with laymen and laywomen, was the dynamic institution of Buddhism which gave the religion its vitality and its validity. In the Pāsādika Sutta the Buddha tells Cunda how the stability of the religion depends on the achievements of this fourfold assembly which includes both Bhikkhunis and laywomen, showing that women were by no means an appendix but an integral part of the corpus of the religion (Santi kho pana me cunda etarahi therā bhikkhū sāvakā vyattā vinītā visāradā ... therā bhikkhuniyo sāvikā ... upāsakā sāvakā ... upāsikā sāvikā ... Etarahi kho pana me cunda brahmacariyaṃ iddhañ ca phītañ ca vitthārikaṃ bāhujaññaṃ puthubhūtaṃ yāva'd'eva manussehi suppakāsitaṃ. D.III.125f.). This significance of the Bhikkhunī Sāsana is further attested in the Mahāparinibbāna Sutta, where heedless of an anachronism, it is said that the Buddha, not long after his enlightenment, told Māra that he would not pass away into parinibbānauntil his fourfold assembly, including the Bhikkhunis, i.e. Bhikkhu, Bhikkhunī, Upāsaka and Upāsikā, is well and firmly established (Na tāvā'ham pāpima parinibbāyissāmī yāva me ... bhikkhuniyo na sāvikā bhavissanti viyattā vinītā visāradā... sappāṭihāriyaṃ dhammaṃ desessanti. D.II.113). The presence of women in the monastic life is accepted as a reality and most admonitions which were addressed to the Bhikkhus were equally applicable to the Bhikkhunis as well (Yassa kassaci bhikkhave bhikkhussa vā bhikkhuniyā vā kāyavaṅko appahīno kāyadoso kāyakasāvo vacīvaṅko ... manovaṅko ... evampapatitā te bhikkhave imasmā dhammavinayā seyyathā'pi taṃ cakkaṃ chahi divasehi niṭṭhitam. A.I.112f.). However, there soon evolved a separate code of conduct for the use of the Bhikkhunis which took into consideration the differences not only of sex but also of temperament between the Bhikkhus and the Bhikkhunis.
In the study of the Bhikkhu Pātimokkha we have already observed how both the text and the ritual of the Pātimokkha grew out of the restrictive regulations which the Buddha had to lay down from time to time to discipline the monks who were leading the life of brahmacariya under him (Yannūnā'haṃ yāni mayā bhikkhūnaṃ paññattāni sikkhāpadāni tāni nesaṃ pātimokkhuddesaṃ anujāneyyaṃ. Vin.I.102). As this first collection of the Bhikkhu Pātimokkha grew, associated for the most part with monks alone, some of its rules no doubt came to possess a peculiarly masculine relevance. Nevertheless, the Pātimokkha as a code meant to further the life of brahmacariya would have applied in its essence to the women as well when they sought admission to be ordained as Bhikkhunis under the Buddha. Recognising the character of woman from diverse angles, both social and religious, the Buddha had to make relevant changes in the Pātimokkha of the Bhikkhus to make it acceptable to the Order of the Bhikkhunis. Yet it remained essentially the same, the guide to the monastic life of those men and women who renounced the world.
The evolution of the Bhikkhunī Pātimokkha out of the Pātimokkha which was laid down for the Bhikkhus seems to have confused some scholars considerably with regard to its size and contents.1 We shall therefore first examine this phenomenon. The regulation of the discipline of the newly established Bhikkhuniī Sāsana does not seem to have necessitated any structural alteration of the original Pātimokkha. The original classification of sikkhāpadainto different categories is accepted in the Bhikkhunī Pātimokkha, almost in toto, the group of Aniyatas of the Bhikkhu Pātikokkha being the only one to be left out in the latter. On a closer examination, however, it would be discovered that these two Aniyata dhammas are themselves a further development out of the Bhikkhu Pācittiyas 44 and 45 which have been made applicable to the Bhikkhunis as well. On the other hand a number of individual rules which are peculiar to the male members alone had to be left out while a host of new rules came to be added to cover the special needs of the women in the monastic community.