The world of animals in captivity offers us at once a prophetic glimpse and a caricature of the world in which modern man lives out his life. The animal suffers psychologically and his suffering is not unlike that of man himself, since its world is characterized by deterioration of its environment and by its own degradation. The causes are the same in both cases: the increase in the number of individuals occupying a limited amount of space and the necessity for existing in a society in conflict with nature. Just as men occasionally reject society and retreat into a misanthropic solitude which sometimes impels them to murder, so, too, animals in a zoo—baboons, for example—suffer from, and are deformed by, lack of sufficient space for them to lead a harmonious social existence. When captivity has done its work and an animal has become truly dangerous, it then becomes necessary to isolate it in a cage of its own.