Problems arising from a lack of civility are illustrated by two theories known respectively as the theory of "shattered windows" and of "zero tolerance". The author describes both theories, as well as the results of their application in New York City, where criminal behaviour has fallen dramatically. But while criminal behaviour involves breaking the law, incivility, or offensive behaviour, consists merely of a breach of custom or a violation of accepted rules (such as the writing of graffiti). All statistical studies show that the feeling of insecurity is triggered by a significant rise in offensive behaviour, rather than by an increase in crime.
Supported by statistical studies, the author argues that the distinction between offensive behaviour and crime is an important one. But it must be borne in mind that since the first can lead to the second, all forms of offensive behaviour must be punished according to their seriousness. In other words, rules must be respected and applied, so as to keep the various forms of incivility from escalating into law breaking. The author argues that crime prevention relies on the punishment of offensive behaviour.
The main difficulty lies in judging how to punish incivility. The author believes that the measures taken in New York and other large metropolitan centres cannot be applied to the French situation, given both the absence of a municipal police force and the French attitude toward law enforcement. He believes that the struggle against incivility will have to be carried out by social service workers. He then proceeds to examine a series of measures and to evaluate their efficiency quantitatively.

Sebastian Roché is senior fellow in sociology at the Centre National de la Recherche Scientifique and a renowned expert on security. He is frequently consulted both by local authorities and by government ministers.