Wilford : Medium rare? And this train is a closed ecosystem. We must always strive for balance. Air, water, food supply, population must always be kept in balance. For optimum balance, however, there have been times when more radical solutions were required. When the population needed to be reduced, rather... drastically.
Wilford : We don't have time for true natural selection. We would all be hideously overcrowded and starved waiting for that. The next best solution is to have individual units kill off other individual units. From time to time, we've had to stir the pot, so to speak. The Revolt of the Seven, the MacGregor Riots, the Great Curtis Revolution.