Working definition. A threshold is both boundary and passage: the place where crossing changes the meaning of what lies on either side.
Inherited meaning
Architecture gives the threshold physical form; ritual gives it temporal form. Initiations, departures, and transformations often include a liminal interval in which an old identity no longer holds and a new one is not yet secure.
Meaning in the imagination economy
The years after the cost collapse are a threshold. Execution is no longer the old constraint, yet institutions, identities, and ethics still assume it is. Threshold thinking resists two temptations: pretending nothing changed and pretending the destination is already known.
What changes in practice
Mark what has ended, what remains unresolved, and which experiments are safe enough to begin. Build temporary practices that help people cross without mistaking provisional answers for permanent architecture.