“Nulla crimen sine lege.” Like all truisms, “no crime without law” conceals as much as it reveals. In particular, it leaves open the question of how law is defined. It is society, of course, that defines some acts or omissions as crimes, and which acts are considered tolerable or intolerable depends upon the prevailing local culture. Having said that, there are some acts that would receive almost universal condemnation – “almost” because, in every case, small exceptions can be adduced. This section reviews the various legal traditions and philosophies of punishment and crime control. What works for one country may or may not work for others because of deep-rooted cultural beliefs and attitudes. These cultural differences often make it difficult to achieve international agreements in dealing with international and transnational crimes.

There are three major legal traditions that can be found worldwide: civil law, common law, and Islamic law (though some societies follow indigenous traditions where the problems are solved informally without any prescribed codified law). Each legal tradition deals with substantive law (defining crime and specifying punishments) and procedural law (the details of the adjudicatory process and judicial review). Each of these traditions has its own merits in dealing with crime and, in the modern world, most countries incorporate elements of other legal systems into their own laws (see Chapter 9 by Matti Joutsen).

In all legal traditions, punishments for breaking the law vary according to the perceived severity of harm. Two principal punishment philosophies vie with each other – utilitarianism and retributivism – each of which achieves ascendancy in certain situations. The former focuses on deterrence to preserve social order, while the latter focuses on moral order whereby the individuals are held responsible for their crimes (see Chapter 10 by Graeme Newman).