concerning moral imperative, you can apply it on the characters' conscience and morality...write about their different attitudes and how some of them don't care about morality though pretending to be the opposite...write how some of them would consider the witchcraft trials to avenge them selves towards others...and how those who are accused of practicing witchcraft have either to confess or to face the sentence of death and their decision deends on their sense of morality...you can write also how some refuse to name people accusing them illogically simillar to what was happening during the McCarthy Era during 1960s....
please, note that this is my own understanding that could be right or wrong,,,wish u all the best