Xjyuk

On what basis can a person who chooses to forgo enlightenment (arahant status) for any reason (for the supposed benefit of others, for example) be considered a Buddhist? If there is such a basis, can a person who intentionally retains a wrong view (seeing the body as self, for example) also be considered a Buddhist when they won't renounce such a view once corrected? Or a person who intentionally retains wrong action (stealing), saying that such action benefits others? I am mostly referring to the choice some people make to be a "bodhisattva" when they see that choice as intentionally putting off the efforts and strivings necessary to become enlightened because they would rather work "selflessly" for others' benefit. Where is the support for such a choice found within the Buddha's teachings?

It's a dangerous question, because it invites potential arguments between supporters of particular sects, but I will try to answer in good faith anyway.

The goal of Buddhism is attainment of Nirvana. For simplicity, let's characterize Nirvana as "unconditional peace". As per the Noble Truth such unconditional peace is only possible when there is absolutely no craving. Now, what is craving? Craving is an obsessive desire for something other than what is present here and now. The absence of craving then is 100% satisfaction in the here and now. Such satisfaction can only be unconditional if craving is absent regardless of circumstances. In other words, unconditional peace is the absence of craving for the circumstances to be different than they are now.

Achieving this level of absence of craving and thus mastering the unconditional Peace is the culmination of the Noble Eightfold Path. Now, if someone has attained this Peace, would they have an inner reason to stay away from society? If we think logically, the answer must be a firm and resounding "no!". For one, because in the absence of craving there can't be aversion to society. Second, unconditional peace is, by definition, imperturbable. Finally, staying in society creates possibilities for teaching Dharma, which helps reduce global level of suffering^†, something a true self-less Buddhist would be happy to facilitate.

So, as it turns out, an already Enlightened mind would absolutely choose to stay in society to keep helping others.

Now, if an Enlightened mind (~"a Buddha") would lead such lifestyle, why wouldn't we, his students, model after our teacher and lead the same lifestyle even now, before we are fully enlightened? Especially if working on our own Enlightenment, it turns out, is not in conflict with "staying behind"! In fact, upon a closer examination, dropping our aversion to society and our craving for a trascendental escape, is exactly the kind of "letting go" that is required for attaining the unconditional peace of no-craving.

So if we can drop our aversion to society, accept everything in its imperfection, and help other sentient beings reduce the level of dukkha, by abandoning craving - turns out we are de-facto living the state of Buddha that we have supposedly forgone! But if we abandon society and work on our own Liberation, it turns out we in fact are acting out of our selfish aversion and selfish craving! So the path of a Bodhisattva is logically consistent with Dharma while the path of an arahant hides a logical contradiction. Or perhaps the path of an arahant may be a valid provisional training, but at the advanced stages if one were to truly abandon craving, the switch over to Mahayana would happen anyway.

And this is roughly the line of reasoning that led to emergence of Mahayana's ideal of Bodhisattva. I may have made some small mistakes in connecting the chain of ideas, but the overall argument is more or less right, I think.

I can't speak for edge cases though. There's obviously a possibility that someone would use this logic to cover up their laziness and complacency. They may even have false views regarding the self, and engage in dukkha-creating activities such as stealing. This is not out of question. But this does not negate the core idea of Mahayana, which is based on the valid understanding of The Goal, The Second and Third Noble Truths, and their real-life implications.

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^†@Dhammadhatu - note how this says "global level of suffering" without mentioning any sentient beings.}

In Theravada, stream-enterers, once-returners & non-returners have eradicated the view the five aggregates are a real self. However, they may have the ridiculous impossible aspiration to save others. While the Pali suttas say it is not possible to save all sentient beings, the Pali suttas also refer to "rebirth by aspiration" (MN 120). While the meaning of MN 120 may not be absolutely clear, it provides some doctrinal support that a Mahayana Bodhisattva can choose their future course.