Conrad Hermann Hubertus Maria Apollinaris Josten (7 June 1912 in Neuss, Germany – 10 July 1994 in Neuss), known as Kurt Josten or C. H. Josten, was a historian of science and Curator of the Museum of the History of Science, Oxford in England.
In 1921 to 1929, Josten was educated by the Jesuits at Bad Godesberg in Germany. He studied for a year at the Staatliches Gymnasium in Neuss, followed by studies at the University of Geneva, University of Freiburg, and University of Bonn. In 1934 Josten worked in the office of the then Vice-Chancellor Franz von Papen, where he was involved in conservative plots to use the extensive powers of the aging President von Hindenburg - in particular his supreme command over the army - in order to stymie a complete grab of power by the Nazi members of the Government. When those aspirations came to a bloody end during the occupation of the Papen-Offices by the SS during the Night of the Long Knives on 30 June 1934, Josten scarcely managed to escape while his immetidate superior Herbert von Bose was shot and other members of the Papen staff were arrested and taken to Lichtenburg Concentration Camp.
In 1935 Josten achieved a doctorate in law from the, University of Erlangen. However, he gave up law due to disillusionment about the state of law in Germany under the Nazis. Also in 1935, he visited England, including Oxford.
Jostem opposed Nazism from 1934 onwards and went into hiding in 1943 in Paris, France and then Bavaria in German. After World War II, he returned to England and eventually became a naturalized British citizen in 1954.