Looking for ideas on this notion I came across posts from Don Reekie. Not exactly a crucible but a space that is more than a physical construction. A space for truth.
http://www.donreekie.com/2010/04/stage-a-wonderful-and-particular-place-in-reality/
http://www.donreekie.com/2010/04/staging-and-reality/
What happens when we step out of ordinary reality onto the psychodrama stage is that the metaxy comes alive, the medial world lives, the soul can live.
This happens as many principles come into play. One is containment. Restraint. The container of the stage is like the alchemical crucible. It must not break. For the work to be done the vessel must hold even when it boils and shakes.
It is a therapeutic relationship, a marriage, a church. Temenos.
This is on my mind as I think of a dialogue as a way of creating a crucible for truth about what is usually invisible… matters of mind and imagination. Dialogue goes beyond a good conversation.