I saw it as a different discussion because the "what is a person's duty?" is a different question than "does a person have a duty?". But you might be right, th

I saw it as a different discussion because the "what is a person's duty?" is a different question than "does a person have a duty?". But you might be right, the evolution of morals that we've seen in the last 75 years might have killed the concept of Duty as a byproduct - because we no longer accept the same things as our Duty, nothing replaced them and the whole concept died.