Stefan wrote:Is Nibbana (or at least sotapatti) possible to attain without a teacher or a kalyanamitta?
There can be no teachings without a teacher, except in the sense of notself.
But all learning, including finding and following the right teacher, is self-learning. A teacher cannot force an student to learn what they have no interest in learning, either through belligerence, psychological manipulation, supernatural powers, or magical rituals.
I don't think that's what you mean, though, but a specific kind of religious teacher. You're asking: Does a person need a guru, a swami, a rabbi, a priest, an ordained Buddhist monk, to be enlightened? And I'd say the answer is no, citing pratyekabuddhas as an example. However, teachers themselves are very valuable, although often our best teachers are merely our closest relatives and friends. But our greatest teacher is always ourselves and it is only a matter of listening to it, with mindfulness, and applying what we know.
From the Dhammapada:"Though a fool, through all his life, associates with a wise man, he no more understands the Dhamma than a spoon (tastes) the flavour of soup.
Though an intelligent person, associates with a wise man for only a moment, he quickly understands the Dhamma as the tongue (tastes) the flavour of soup."
(So, mindfulness is more important than a steady, long-term teacher-disciple relationship)"Oneself, indeed, is one's saviour, for what other saviour would there be? With oneself well controlled one obtains a saviour difficult to find."
(So, teachers are only guides, never saviors)
But positive associations are also important! See the quote in my signature.