Thank the nonexistent gods of Karl Marx that Arthur Miller wrote The crucible so I could imagine the blacklist.
KS: Well, every actor has to get through his Shaw crucible.
The only individuals and entities that do learn are those that have personally experienced—and endured—the crucible of crisis.
early 15c., from Medieval Latin crucibulum "melting pot for metals," originally "night lamp." First element might be Middle High German kruse "earthen pot." Or perhaps it is from Latin crux on some fancied resemblance to a cross. Used of any severe test or trial since 1640s.