Acts of crime have been recorded throughout the history. While the crimes may have been changing with age, the definition of crime has basically remained focused on the deviation from what is social acceptable. There are different theories of crime which have been developed to explain why individual engage in crime and formulate and model that can be used to deter crimes. However the classicist and the positivism approach have remained the key to models that are used to explain causes of crime and the criminal justice system. This paper will compare the classicist and the positivism approach to crime discussing their view on the causes of crime and the dual process of trial, conviction, punishment and deterrence of criminals.