Why are we reading a Shakespeare play or 'Huckleberry Finn?' Well, because these works are great, but they also tell us something about the times in which they were created. Unfortunately, previous eras and dead authors often used language or accepted as normal sentiments that we now find unacceptable.
I've studied pathological liars, and anything they say, they believe, and that's one of the reasons they're so convincing, because they have no connection with the truth. It's a dead issue. It's like they're color-blind to the truth. So anything that comes out of their mouths is their reality.