I don't believe there is a hard line. It depends on two things:
1. How well you make your argument, because the art of speech is really what makes or breaks a social construct.
2. What kind of events have occurred since the death of the person. Normally it would be frowned upon to open the casket of someone who died only 20 years ago, but imagine Nightfall occurred and left humanity with only very few survivors. Knowledge of the old world would wind up being lost much faster, raising the value of sepulchral culture at a much greater speed!
un: werther
1. How well you make your argument, because the art of speech is really what makes or breaks a social construct.
2. What kind of events have occurred since the death of the person. Normally it would be frowned upon to open the casket of someone who died only 20 years ago, but imagine Nightfall occurred and left humanity with only very few survivors. Knowledge of the old world would wind up being lost much faster, raising the value of sepulchral culture at a much greater speed!