People have always cheated. Look at the French income tax system. Not only can civilization be wrecked by the loss of a single generation, it can also be broken down by 48 hours of hunger or thirst after a disaster. One interesting contrast happened in Kobe, Japan after the earthquake there. Consensus doesn't do it.
Nazis can become a majority.
Yes, I mentioned that previously. This majority can be religiously or politically guided. I have long since admitted that I cannot give you absolute justification for moral axioms. And we have agreed that all standards are accepted on the basis of personal belief. You justify it on your belief in God and your beliefs about God.