"Invariably, a wise and liberal communication of liberty has the effect of appeasing instead of inflaming the passions. But more than this, where the population only feels the pressure of their government, they are apt to herd together like miserable sheep; they are unconscious of any other danger than that which stares them in the face and take little or no account of each other's actions, although these exercise so wide and so constant an influence upon the public weal. I think if anyone will follow carefully and minutely the workings of American society, he will find that the people are as much occupied in keeping each other in order as they are in checking the authority of their governments. It is only by doing the first that they succeed in doing the last."
-- Frederick Grimke, The Nature and Tendency of Free Institutions
(1968 ed., p. 197).
In other words, free society promotes personal responsibility. Good behavior is more effectively fostered by social pressure than by the police.