The author sees his work as an emphatic plea for a theoretical history of science and the humanities. As a retrospective study of its own discipline, the history of historiography is at the same time methodical self-reflection, it is history. The author tackles three tasks which are systematically connected: 1. He reconstructs the scientific history of history in the past 250 years as a sequence of the three scientific paradigms »history of the Enlightenment,» »historicism» and »social science history.» 2. He provides a historical outline of the science of history since the middle of the 16th century, since humanism, which was so important for Europe‹s historical self-perception. 3. He traces the history of historiography in detail. His study is based on theoretical historical manifestos and on a wealth of evidence from the history of historiography. It also incorporates little known published material and unknown manuscripts as sources into the theoretical interpretation.