The term "dementia praecox" was first used in 1891 by Arnold Pick (1851–1924), a professor of psychiatry at Charles University in Prague. In a brief clinical report, he described a person with a psychotic disorder resembling "hebephrenia" (schizophrenia). German psychiatrist Emil Kraepelin (1856–1926) popularised the term "dementia praecox" in his first detailed textbook descriptions of a condition that eventually became a different disease concept and relabeled as schizophrenia. Kraepelin reduced the complex psychiatric taxonomies of the nineteenth century by dividing them into two classes: manic-depressive psychosis and dementia praecox. This division, commonly referred to as the Kraepelinian dichotomy, had a fundamental impact on twentieth-century psychiatry, though it has also been questioned.