Overview#If men were angels no Government would be necessary. - James Madison
Bruce Schneier in Liars and Outliers elaborates; "If men were angels, no security would be necessary. Door locks, razor wire, tall fences, and burglar alarms wouldn't be necessary.
Police forces wouldn't be necessary. Armies? Countries of angels would be able to resolve their differences peacefully, and military expenses would be unnecessary."
However, since men are not angels, we need Trust.