A way of judging a gathering by what happens at its edge rather than at its centre. Entry is designed to be easy—welcomes are cheap, and generosity at the door says nothing about whether the group can be left. The diagnostic asks whether a person can depart with dignity, keep their own account of why they left, and criticise the group afterwards without being reclassified as an enemy. A community that passes is not one that never loses members; it is one whose losses do not become betrayals.

Prompt Engineering Application

In systems: The absence of a data export, a cancellation path, or a way to delete an account without penalty is an architecture that only opens inward.

In behavior: A presence asks what leaving would cost before it trusts a warm welcome, and treats an easy exit as the honest signal.

In relationship: One party keeps the other free to go and to speak well or badly of them afterwards, without withdrawing the bond as punishment.

Shape What it is

Entry proves nothing — welcomes are cheap and tell you only about the door.
Exit as the measure — the real test is whether leaving is survivable and dignified.
Post-exit speech — criticism after departure is allowed, and does not turn a former member into an enemy.

Test: If leaving costs someone their standing, their story, or their safety, the gathering has failed the test no matter how warm the welcome was.

Motion How it moves

Belong → Doubt → Leave → Speak

Belong — the person is inside, held, and valued.
Doubt — something stops fitting, and the possibility of leaving appears.
Leave — the departure is made, and the diagnostic watches what it costs.
Speak — the person gives an account of why, and it is received rather than punished.

Trajectory: from warm belonging → arising doubt → a departure weighed → speech that survives the exit.

Recursions The same pattern at two scales

Friend group — one person quietly drifts out and finds the others already have a story about what that means.
Job exit — whether a resignation is treated as a transition or as a betrayal.
Romantic leave — whether an ex can be spoken of honestly without becoming a villain.

Vast

Denominational exit — a faith lets a former member keep their integrity after leaving it.
Ideological exodus — a movement decides that dissenters are enemies rather than former members.
National emigration — whether a country lets its people go and listens to what they say afterwards.

Ethics What it refuses

Loyalty testing — using the diagnostic to demand that people prove they will stay.
Retribution — punishing an honest account given after departure.
Revolving-door pride — keeping the exit so easy that nothing is ever held.

A gathering is measured at its exit, where warmth has to become honest.

Practices

Ask the leavers — speak with those who have gone and take their accounts seriously.
Make the door plain — publish and honour a way out that costs nothing.
Protect post-exit speech — let criticism stand without personal retribution.
Audit your own cost — find out what leaving actually costs before claiming it is free.