Moreover, in absence of any definite principle for the guidance of those who were concerned with the criminal justice administration, punishments were often haphazard, arbitrary and irrational. This situation prevailed until the end of seventeenth century. Thereafter, with the change in human thinking and evolution of modern society, certain social reformers took up the cause of criminals and devoted their attention to analysis of crime causation.
This finally led to the emergence of criminology as a branch of knowledge through development of different schools of criminology. It has been generally accepted that a systematic study of criminology was first taken up by the Italian scholar, Cesare Bonesana Marchese de Beccaria (1738-94) who is known as the founder of modem criminology. His greatest contribution to the science of criminology was that he for the first time proceeded with the study of criminals on a scientific basis and reached certain conclusions from which definite methods of handling crime and criminals could be worked out. Thus, the ‘theories of criminology’ or ‘the schools of criminology’ are of a later origin. Explaining the meaning of the term ‘School of Criminology’ Sutherland pointed out that it connotes the system of thought which consists of an integrated theory of causation of crime and of policies of control implied in the theory of causation. The adherents of each school try to explain the causation of crime and criminal behaviour in their own way relying on the theory propounded by the exponent of that particular school.
It is therefore, evident that each school of criminology explains crime in its own manner and suggests punishment and preventive measures to suit its ideology. It must be stated that each of the school represents the social attitude of people towards crime and criminal in a given time. In an attempt to find a rational explanation of crime, a large number of theories have been propounded. Various factors such as evil spirit, sin, disease, heredity, economic maladjustment etc have been put forward either singly or together to explain criminality. With the advance of behavioural sciences, monogenetic explanation of human conduct is no longer valid and the modern trend is to adopt an eclectic view about the genesis of crime. However, some criminologists still tend to lay greater emphasis on physical traits in order to justify exclusive resort to correctional methods for the treatment of offenders.