In criminology, the Classical School usually refers to the 18th-century work during the Enlightenment by the utilitarian and social-contract philosophers Jeremy Bentham and Cesare Beccaria. Their interests lay in the system of criminal justice and penology and, indirectly, through the proposition that "man is a calculating animal", in the causes of criminal behaviour. The Classical School of thought was premised on the idea that people have free will in making decisions, and that punishment can be a deterrent for crime, so long as the punishment is proportional, fits the crime, and is carried out promptly.