Although members of civilization may protest the laws that control their daily lives and contest in opposition to government power on principle, civilization could not function properly without laws and without criminal regulation in particular. For centuries, many have viewed the principle of criminal law and the overall government and legal system as essential to the “good functioning of society and the preservation of order” (Duff, 2008). This view of criminal law sees it as part of the social arrangement designed by Thomas Hobbes. Others argue that the purpose of criminal law is to keep society safe from those who cannot obey society's rules or to penalize those who violate society's norms (Duff, 2008). However, criminal law can best be seen as having the intent to fulfill all these requirements for society. In the United States, there are several sources of penal governance. Criminal law is usually the one recognized by legislative bodies, as the Constitution grants them the freedom to do so (Meloy, 2008). Courts' analysis of what written law also provides a basis for criminal law because it tests what people can or cannot do that is considered criminal or illegal (Meloy, 2008). The United States has a very contradictory legal system. The system was intentionally designed to be adversarial to ensure that the courts are impartial to all parties. An adversary is an individual “who argues with, is against, or opposes” another individual, “an adversary” (Adversary, 2010). Although defense lawyers and prosecutors in illegal cases hate each other in an illegal case, the two are actually significant and essential in criminal law. ...... half of the document ...... retrieved March 1, 2012, from http://www.merriam-webster.com/dictionary/adversaryCRS Annotated Constitution. (2010). Cornell University School of Law. Retrieved March 1, 2012, from http://www.law.cornell.edu/anncon/html/amdt5bfrag1_user.htmlDuff, A. (2008). Theories of criminal law. Stanford Encyclopedia of Philosophy. Retrieved March 1, 2012, from http://plato.stanford.edu/entries/criminal-law/Meloy, M. (2008). Law and crime. Rutgers University. Retrieved March 1, 2012, from http://crab.rutgers.edu/~mlmeloy/courts_ch.2_law_and_crime_1_24_08.pptRobinson, P. H. (1999). Mens Rea. University of Pennsylvania. Retrieved March 1, 2012, from http://www.law.upenn.edu/fac/phrobins/mensreaentry.pdfStevens, M. (2003). Incomplete crimes (in the early stage). California State University Fresno. Retrieved March 1, 2012, from http://faculty.ncwc.edu/mstevens/293/293lect05.htm