[Survived]

I think Bonhoeffer was referring to an acquired or affected stupidity; a position adopted defensively to fit into a social or political situation.

If the truth becomes dangerous or unpopular, a decent defense is adopting stupidity. I think that is subtly different from ignorance, which implies never knowing, as opposed to a rejection of truth.

Like much cognitive dissonance, it can be easiest to live with if you just change your beliefs rather than trying to rail against it.

The danger is, once truth is denied, reality becomes disconnected and atrocity much more abstract.

Maybe there is a better name yet for the phenomenon.