– You can also think of it this way, this comes from my own understanding and contemplations. Imagine yourself as cause and effect, how would you keep the party going or Sansara or effects? If there are no causes, can this universe exist? Who or what provides the causes for effects to take place?
“Why can’t ignorance rise again?”
– Based on what Lal said, as well you can find clues to your question on what is a Satta and what Sakkaya samudaya, sakkaya nirodha.
– Ignorance doesn’t need to rise again, because ignorance is what this world is or cause and effect or Paticca Samuppada. This is how it is and always will be. This isn’t confirmed by anyone, just my belief as of this moment from my contemplation, observations and evidences that I see in the Buddha Dhamma. I believe this world or universe or cause and effect nature is avija (ignorance) and being in this world is very unfavorable for us living beings. The most obvious evidence pointing to this is the three characteristics of this world, Anicca, Dukkha, Anatta and others. The only saving grace of our existence is being able put a stop to the rebirth process, or being able to cultivate wisdom to remove the avija (ignorance) as a Satta. But ignorance will always remain and be a part of what this world is or cause and effect.
“Even if an infinite number attain Nibbana, there ALWAYS will be an infinite number left.”
– I wonder why is that so. :) My answer would be what I have written above.