As with manners, most laws do not prescribe behavior that is ethically required. As with manners, the main factor accounting for compliance with laws is custom. As with manners, most laws do not have strict penalties awaiting those who transgress them. As with manners and other customs, laws vary from society to society.
A law is successful primarily because the behavior it prescribes has attained the status of custom. Just as manners are observed not because of sanctions attached to them but because, through repetition, contrary behavior becomes unthinkable, so societal laws are obeyed not because the behavior is ethically required or because penalties await those who act otherwise, but because to act otherwise would be uncustomary.
Which one of the following comparisons is utilized by the argument?