„This is what occasioned medieval custom: usages were introduced under the pressure of circumstances; some of them fell into disuse; other were immediately fought, others in the end were accepted or merely tolerated by the group as a whole and soon acquired the force of custom. It was thus that rents, for example, were very early fixed in very diverse ways according to domain. Now, once accepted on both sides and collected for a certain time, there could no longer be a question of abolishing them: it was necessary to wait for them to disappear of themselves. Custom, usage that was lived and tacitly approved, governed the life of the human group and constituted obstacles to individual caprices. Of course there were always individuals who tried to jump over the obstacles that the group or society set up, but then the matter fell into the category of an infraction, such as a delinquent does today; and if no public power to sanction offenders existed, the latter were rejected by the group, which amounted to the same thing, especially in a time when life was difficult for an isolated person.”
— Régine Pernoud, Those Terrible Middle Ages, str. 70.