Arnold J. Toynbee quotes - page 3
Of the twenty or so civilizations known to modern Western historians, all except our own appear to be dead or moribund, and, when we diagnose each case, in extremis or post mortem, we invariably find that the cause of death has been either War or Class or some combination of the two. To date, these two plagues have been deadly enough, in partnership, to kill off nineteen out of twenty representatives of this recently evolved species of human society; but, up to now, the deadliness of these scourges has had a saving limit.
Arnold J. Toynbee