The effects of plenty and hunger

Ibn Khaldun determined that the people of the deserts, who lack grain and condiments and rely only on milk and meat, are in better condition in their bodies and characters than the people of the settled hills who are immersed in comfort. Their complexions are clearer, their bodies purer, and their minds sharper in knowledge, because an abundance of food produces bad residues in the body and vapours that cloud the mind, leading to dullness and heedlessness. He observed this in the animals of the desert, such as the gazelle, the ostrich, and the oryx, compared with similar animals of the settled land. The effect shows even in religion and worship: the ascetics are better in religion than the people of luxury, and the existence of devotees and renouncers is confined to the ascetics. When famines strike the affluent, destruction comes to them quickly, as with the Berbers of the Maghrib and the people of Fez and Egypt, unlike the Arabs of the desert. ²

What is not recorded here needs a further source.