The Italian positivists (Ferri, Carrara, Lombroso) first used the word criminology and struggled with numerous theoretical problems to separate the field of criminology from the already existing penal sciences. Their definitions focused on both the facts of criminal behavior and the reaction of society to crime. However, even before this official starting point, several other fields (psychiatry, social hygiene, morality) had attempted to look at criminal behavior in a scientific way. From then to the Chicago school of sociologists to today, the struggle to delimit criminology and to avoid simplistic definitions persists.