Nibbana for all?

[Jetavan]

Is there a sutta in which the Buddha talks about how many beings will (eventually) realize nibbana? Will all eventually realize nibbana? I seem to remember him being asked that question, and him not giving an answer.

[culaavuso]

In the same way, the Tathagata isn't concerned with whether all the cosmos or half of it or a third of it will be led to release by means of that [Dhamma]. But he does know this: 'All those who have been led, are being led, or will be led [to release] from the cosmos have done so, are doing so, or will do so after having abandoned the five hindrances — those defilements of awareness that weaken discernment — having well-established their minds in the four frames of reference, and having developed, as they have come to be, the seven factors for Awakening.

[Aki]

...how many beings will (eventually) realize nibbana? Will all eventually realize nibbana?...

As in DN 16, Mahāparinibbāna Sutta, it depends on how many beings will follow the Path:

"Devoid of true ascetics are the systems of other teachers. But if, Subhadda, the bhikkhus live righteously, the world will not be destitute of arahats."

[Jason]

Is there a sutta in which the Buddha talks about how many beings will (eventually) realize nibbana? Will all eventually realize nibbana? I seem to remember him being asked that question, and him not giving an answer.

There are two places in Pali the Canon where this is addressed that I'm aware of. The first is AN 10.95, where Uttiya the wanderer, after asking a number of other metaphysical questions, asks the Buddha if all the world will reach release, or a half of it, or a third. In this instance, the Buddha remains silent, and Ananda gives an analogy to explain the Buddha's silence:

• "Uttiya, suppose that there were a royal frontier fortress with strong ramparts, strong walls & arches, and a single gate. In it would be a wise, competent, & knowledgeable gatekeeper to keep out those he didn't know and to let in those he did. Patrolling the path around the city, he wouldn't see a crack or an opening in the walls big enough for even a cat to slip through. Although he wouldn't know that 'So-and-so many creatures enter or leave the city,' he would know this: 'Whatever large creatures enter or leave the city all enter or leave it through this gate.'
  
  "In the same way, the Tathagata isn't concerned with whether all the cosmos or half of it or a third of it will be led to release by means of that [Dhamma]. But he does know this: 'All those who have been led, are being led, or will be led [to release] from the cosmos have done so, are doing so, or will do so after having abandoned the five hindrances — those defilements of awareness that weaken discernment — having well-established their minds in the four frames of reference, and having developed, as they have come to be, the seven factors for Awakening. When you asked the Blessed One this question, you had already asked it in another way. That's why he didn't respond."

The second reference is in the Questions of King Milinda, a later work that's included in the Khuddaka Nikaya of the Burmese edition of Pali Canon, but not in Thai or Sri Lankan versions. Here, King Milinda asks whether everyone attains nibbana, to which the Ven. Nagasena (an arahant who's thought to have lived some time around 150 BCE) responds:

• “Not all, O king; but whoever conducts himself rightly, understands what should be understood, perceives what should be perceived, abandons what should be abandoned, develops what should be developed and realises what should be realised; he attains nibbāna.”