Lu Ch'un-yang was one of the great Taoist immortals — an adept with the whole range of attainments, the sort of figure other practitioners travel to meet. He met Huang-lung Nan, an enlightened Zen master, and could not tell he was anything other than an ordinary monk.1
Nothing was hidden from him. He looked with everything he had, at a man who had finished the thing they were both doing, and saw a man in robes. That's the problem this page is about, and it isn't a story about one man's bad day — it's the standard case. The pattern named around it is that the master with lower attainment routinely knows nothing of the higher one's achievements, and challenges them, having concluded from the absence of display that there was nothing there.2
Here's the structural fact that makes the mistake unavoidable. Some Arhats deliberately cultivate the supernormal abilities and have them. Others cultivate only wisdom, put no effort into the physical side at all, and therefore don't have them.3 Both are Arhats. The stage is the same; the equipment differs, because equipment is a separate line of work.
The reason is spelled out. Even at enlightenment you don't automatically get the ability to fly or walk through walls, because those require the physical nature to have been transformed as well — the wisdom body and the other two are different attainments.4 Great wisdom gets you to see your own nature and wake up. Your body then still needs its own time and its own work. So powers are evidence of one specific kind of cultivation, not of altitude.
Most people run this test in one direction and get warned about that direction only: don't assume someone is a great Arhat because they can do something impressive. Others can produce similar effects without having the attainment at all.5
The second direction is the sharper one and gets said less often. Absence of powers is not absence of attainment. It's exactly what a wisdom-only practitioner looks like, and there are many of them, and there is no external difference between one of those and a person with nothing. Which leaves the honest position: from the outside, by way of displays, you cannot rank anybody. That's why the corpus keeps returning to behaviour and wisdom as the measuring sticks — not because phenomena are wicked, but because they don't carry the information people think they carry.
There is a description, and it's deliberately unimpressive. They stay clear in every situation. They've let go of their old habits. And they aren't tied down by reputation or money.6
That's it. That's the whole visible profile of somebody who has finished the Hīnayāna path without cultivating a single power. Nothing on that list would make a stranger look twice, and two of the three are only observable over years — you can't see whether a person is free of their habits in an afternoon, and you certainly can't see whether they're indifferent to their own standing until something is at stake.
The one attainment the tradition rates most highly is the one with the weakest signal.
The counter-example matters, because the powers do get used, and the reason they get used tells you what they're for. When Ananda died, two countries were about to fight over his relics. So he raised his body into the air and let the fire element consume it, so both could have a share.7 Note what that is. Not a demonstration and not a teaching — a logistical solution to a succession dispute, executed with the only tool that would work. And the corpus adds the general form: this is the sort of thing Arhats typically do, to encourage faith in the path.8
So the display has a stated purpose and it's external. It's for other people, at a moment when other people need something. Which is consistent with the split: a practitioner who never expects to be in that position has no reason to build the capability.
Underneath all of this is the rule that makes ranking anyone above you impossible. A second-degree Bodhisattva understands everything a first-degree one has. The first-degree one understands very little about the stages above. In general: the higher always understand the lower, and the lower have no comprehension of the higher until they get there themselves.9
The picture given for it is a family one. Children don't understand their parents. Then they grow up, pass through the same stages, and finally see what their parents were talking about and why they behaved as they did — and none of that was available beforehand, however carefully they watched.10
Which puts a hard ceiling on the whole enterprise of assessment. You can tell that someone is further on than you are. You cannot tell how much further, and you cannot tell it about anyone above you at all.
Somebody in your life has a reputation for depth. Or you've read someone, or sat with a teacher, and you're trying to work out what they've actually got.
Drop the impressive things first — not because they're fake, but because they're uninformative. Anything demonstrable can be produced by someone at a lower stage who worked on producing it, and can be absent in someone who finished and never bothered.
Watch the three instead, and give it years. Are they clear when things go wrong — not calm, clear? Have their habits actually changed, or have they acquired better vocabulary for the same ones? And the one that tells you most: what happens to them when their standing is threatened. Reputation is the last thing to go, so it's the most diagnostic thing to watch.
Then stop. Whatever conclusion you reach caps out at your own level, and if they're above you, you're going to under-read them. The useful move isn't to grade them better. It's to notice that you can't, and to go and do the work that would change what you're able to see.
Run the split on the hardest case in the corpus. Confucius never displayed anything unusual. No feats, no marvels. The obvious conclusion is that there was nothing to display — and by the reasoning here, that conclusion is unavailable, because a wisdom-only attainment produces exactly this evidence.
The corpus takes the other option: he may have had them and refused to use them, out of discipline.11 The support is a small specific fact rather than a claim about his greatness. He knew perfectly well about the world of spirits, and declined to discuss spirits or unnatural phenomena. That's a policy, which is not what having no view looks like.
Now set him beside Milarepa, who displayed transformations constantly. Two men, both held to be finished. One left a record full of marvels and one left nothing, and the comprehension rule says nobody below either of them can decide between them.
And the two traditions ended up in different states. The one that showed its results left traces later generations could follow back. The one that showed nothing left a text about manners, and it took two thousand years and an argument like this one to suggest there had ever been anything else in it.
The two-kinds split is asserted rather than sourced to a canonical text.12 🚩 SINGLE SOURCE. The Lu Ch'un-yang and Huang-lung Nan encounter is named without citation; the Ananda relic account is a traditional story given without attribution.
A real tension: the corpus says powers are not evidence of attainment, and elsewhere ranks Moses at a deep meditative stage on the grounds that he performed miracles. Both moves are in the same book. Either powers carry information or they don't, and the argument uses them when convenient. Open: if displays exist to encourage faith, and a wisdom-only Arhat can't produce them, does the tradition require some proportion of practitioners to cultivate powers purely as a public function — and is that ever stated as a duty rather than a choice?
Cultivate the powers and you can act when acting is needed — settle the relic dispute, encourage the faltering, meet the challenger. The cost is a lifetime spent on the physical line, and a standing temptation to mistake the equipment for the destination, which the corpus says most who go this way do.
Cultivate wisdom alone and you arrive with nothing anyone can see. You'll be misread by adepts, challenged by your inferiors, and unable to demonstrate anything to a person who needs a demonstration. What you'll have is the thing itself, and no way to hand anyone evidence of it. The corpus prefers the second and keeps telling stories about the first, because the stories are the only transmissible part — which is the same trap it identifies and doesn't escape.
Behavioral mechanics — reading competence off displays. The structure here is general: a visible signal that is genuinely produced by real ability, also producible by people below the level, and optionally absent in people at it. Any signal with those three properties is worse than useless for ranking, and will still be used, because the alternative is admitting the assessment can't be made. That's the mechanism behind credential inflation, behind why the most impressive person in a meeting is rarely the most capable, and behind why a field's genuine masters often read as unremarkable to everyone except each other.
Sharpest implication: the tradition's most valued attainment has the weakest external signal, and its least valued has the strongest — so any community that selects its teachers by what it can observe will systematically select the wrong ones, generation after generation, with no mechanism that would ever reveal the error.
Generative questions: