Emil Wilhelm Georg Magnus Kraepelin was a German psychiatrist. H. J. Eysenck's Encyclopedia of Psychology identifies him as helping to lay the foundation for modern scientific psychiatry, psychopharmacology and psychiatric genetics.
Kraepelin believed the chief origin of psychiatric disease to be biological and genetic malfunction. His theories dominated psychiatry at the start of the 20th century and, despite the later psychodynamic influence of Sigmund Freud and his disciples, enjoyed a revival at century's end. While he proclaimed his own high clinical standards of gathering information "by means of expert analysis of individual cases", he also drew on reported observations of officials not trained in psychiatry.
His textbooks do not contain detailed case histories of individuals but mosaic-like compilations of typical statements and behaviors from patients with a specific diagnosis. He has been described as "a scientific manager" and "a political operator", who developed "a large-scale, clinically oriented, epidemiological research programme". He developed racist psychiatric theories.