The below is a commonly known story about how nuns came into existence in the monastic order.
Buddha's maternal aunt, had asked to be ordained as a nun and had been constantly rejected by the Buddha. Venerable Ananda, on hearing such a sincere request to be ordained, decided to persuade the Buddha to accept the request.
Ananda was rejected outright for two times during that talk with the Buddha. On the third time, Ananda put the request in a different way.
Respectfully he questioned the Buddha, "Lord, are women capable of realising the various stages of sainthood as nuns?"
"They are, Ananda," said the Buddha.
"If that is so, Lord, then it would be good if women could be ordained as nuns," said Ananda, encouraged by the Buddha's reply.
"If, Ananda, Maha Pajapati Gotami would accept the Eight Conditions* it would be regarded that she has been ordained already as a nun."
When Ananda mentioned the conditions to Maha Pajapati Gotami, she gladly agreed to abide by those conditions and automatically became a nun. Before long she attained arahantship. The other Sakyan ladies who were ordained with her also attained Arahantship.
http://www.buddhanet.net/e-learning/buddhism/lifebuddha/2_23lbud.htm
http://www.dailymirror.lk/2006/09/09/feat/1.asp
We all know that Ananda has not attained Arahantship yet at this moment and the reason he persisted was purely out of compassion and not really wisdom as he would not have known the future karmic consequences should women be ordained into the monastic order.
But the fact that he had persisted and hence women can now be ordained into the order and achieve liberation according to the Buddha's teachings.
Second story: When Buddha passed away, there were those who were happy. They had resented the Buddha's nagging and were rejoicing at the news of his death.
When Buddha passed away, Kasyapa was not present. He was leading a group of disciples and preaching somewhere else. When they heard that Buddha had passed away, they rushed back to attend Buddha's funeral. While some monks were crying because of Buddha's death, Upananda, one of the six ill-behaved disciples, seemed to be quite happy. "Why are you crying?" he asked them. "You should be happy! When Buddha was around, he always nagged us and told us that we couldn't do this and we couldn't do that. Now he's dead and we are free from his restraints. We should be happy!"
Kasyapa was quite upset to hear this, because he feared that any monk like Upananda could become a major source of trouble for the congregation in the future. He felt that the most important thing after the funeral was to compile Buddha's sermons and precepts so that every monk could have something to rely on and follow to keep from going astray.
Why did the Buddha accept such disciples since he had the psychic ability to know the karmic links of such disciples and how they might wreck havoc in the congregation should he pass away?
The only reason I can think of other than the Buddha repaying his past evil debts, is that the Buddha is full of compassion. Other than that, it is really not a wise move for a wise and enlightened being like the Buddha.
Ananda could have practised the theory of 'letting go' and not question the Buddha's decision, but he did. The Buddha could have expelled these disciples or not even accept them in the first place, but he did.
Fellow Buddhists, what message can you derive from the above two stories? Let me hear your views.
The impact of accepting 1st female to the male dominated sangha is greater than allowing a less disciplined person to be ordained as monk.
At least that was the condition in India 2500 years ago.
At that time, the sangha are 100% male, so if any female joined them and stay together, it will cause some inconvenience to both the male and female sangha members.
Especially when more and more female ordained, some people may get distracted from the practice.
That is the obvious reasons that we should know, I don't know what other reasons behind this.
Maybe buddha still obverse how the society will adapt to the dharma and sangha before taking next action.
Anyway, in the end, he come out with the 8 conditions for Maha Pajapati Gotami to be ordained. Happy and beneficial ending for both individual and the mass.
Upananda although not a very self disciplined person, but it will be good for him to stay in the sangha and let the group to correct his misconduct.
But of coz under the vinaya rule, if one create trouble that disrupt other member of the sangha, that person will be expelled.
I not sure the exact words, coz I not a monk. :)