The judging of people in the past by the moral standards of the present.
Modern professors advocate presentism and want to reframe historical heroes as villains because they did not conform to modern morality.
"Tear down all the statues of George Washington! The man was a racist!"
"That's presentism, dude. In 100 years someone will probably think you were a monster for eating meat."
There is NO present Caliph of Islam right now.
There is NO present Caliph of Islam right now. All those especially Ahmadiyya Community are spreading lies about their False Caliphs.