The Buddha identified four stages of enlightenment: Stream Entry (sotapanna), the Once Returner (sakadagamin), the Non-Returner (anagamin), and Buddhahood.
The Buddha taught that Stream Entry is attained when the first three of the ten fetters are overcome: Those first three fetters are:
1) Belief in an independent, unchangeable/permanent or everlasting self, called atman in the Vedas, which belief the Buddha called sakkaya ditthi, the wrong view of self;
2) Doubt concerning the teachings of the Buddha, the Buddha Dharma/Buddhadharma; and
3) Belief that chanting, rites and rituals alone could lead to Nirvana.
Modern people can easily agree that chanting, rites and rituals alone cannot lead to enlightenment. The Brahmans of the Buddha’s day apparently practiced a multitude of rites and rituals and apparently placed great emphasis upon them. We can surmise those facts because the Buddha repeatedly denied the efficacy of such practices and he would not have bothered to denounce them unless they were quite widespread.
We also find it easy to overcome doubt in the Buddhadharma because practice rather quickly removes such doubt.
Sakkaya ditthi is the strongest of the first three fetters for most of us. However, it is not that difficult to understand that nothing is permanent. It follows that the Brahman/Hindu belief that cultivation (meditation, sutra study, etc.) changes us into an eternal, perfect, unchanging Atman could not possibly be true.
The Pali word for atman is atta and the Buddha said there is no atta. “No atta” in Pali is anatta, which obviously means no eternal, unchanging, everlasting self.
When we understand that we are not permanent, that we are not eternal, that we keep changing, then we know we have no independent self that is capable of entering into and exiting from existence. Then we have acquired the right view of self, samma ditthi, the first fold of the eightfold path.
A once-returner is one who has cut the first three of the ten fetters (thus attaining stream entry) and loosened the fetters of sense-desire (greed, lust, aversion), and ill will. Notice that these two powerful fetters need only be loosened to graduate from stream entry (sotapanna) to once-returner (sakadagamin) status!
We loosen the fetter of sense desire with Present Moment Awareness and Silent Present Moment Awareness. We loosen the fetter of ill will by practicing metta. Our Beginning Zen practices are important.
A non-returner (anagamin) has cut the five fetters of 1) belief in an independent, everlasting and unchangeable self/atman; 2) doubt; 3) belief that chanting, rites and rituals alone can lead to awakening; 4) sense desire; and 5) ill will.
Our daily practice of metta/loving kindness reduces our ill will. Our daily practice of Present Moment Awareness, and Silent Present Moment Awareness reduces our sense desire and our daily Mindfulness of the Body, the Feelings, the Mind and Mind Objects eliminates our sense desire.
The path that leads from ignorance to Stream Entry is the Eightfold Path and the path that leads from Stream Entry to the Once-Returner and to the Non-Returner is the Noble Eightfold Path according to Venerable Ajahn Brahm, because it is a noble one, one who has entered the stream, who is following it.
And full enlightenment requires dropping the desire to experience the world of form, attained through the jhanas (fetter number six), and the world of formlessness, attained through the immaterial attainments (fetter number seven). And then conceit (fetter number eight), restlessness (fetter number nine), and ignorance (fetter number ten) must still be overcome.
When we drop all of the fetters, we discover that we created the fetters.
And we discover that ignorance created the notion of a self that needed to drop fetters.
