It is easy to show that many societies do not agree with this in practice. The civilised Greeks and Romans regarded other races as barbarians. A shocking example was Aristotle's advice to Alexander to be 'a leader to the Greeks and a despot to the barbarians, to look after the former as after friends and relatives, and to deal with the latter as with beasts or plants'. Many societies based on religion have treated persons of other religions harshly, with little dignity. And sometimes political movements have deliberately and openly talked about and treated some groups as not having human dignity. Nazi treatment of the Jews came after a long period of propaganda against their humanity and dignity.