Therefore, the Negro nation are, as a rule, submissive to slavery, because [Negroes] have little [that is essentially] human and have attributes that are quite similar to those of dumb animals, as we have stated.
Ibn KhaldunWhen incentive to acquire and obtain property is gone, people no longer make efforts to acquire any... Those who infringe upon property rights commit an injustice... If this occurs repeatedly, all incentives to cultural enterprise are destroyed and they cease utterly to make an effort. This leads to destruction and ruin of civilization.
Ibn KhaldunEventually, Aristotle appeared among the Greeks. He improved the methods of logic and systematized its problems and details. He assigned to logic its proper place as the first philosophical discipline and the introduction to philosophy. Therefore he is called the First Teacher.
Ibn KhaldunBeyond [known peoples of black West Africa] to the south there is no civilization in the proper sense. There are only humans who are closer to dumb animals than to rational beings. They live in thickets and caves, and eat herbs and unprepared grain. They frequently eat each other. They cannot be considered human beings.
Ibn Khaldun