No man [or woman], however brilliant or well-informed, can... safely... dismiss... the wisdom of [lessons learned] in the laboratory of history. A youth boiling with hormones will wonder why he should not give full freedom to his sexual desires; [but] if he is unchecked by custom, morals, or laws, he may ruin his life before he... understand[s] that sex is a river of fire that must be banked and cooled by a hundred restraints if it is not to consume in chaos both the individual and the group.