Galileis Verbrechen: Kepler, Galilei und das crimen laesae humanitatis

Johannes Kepler is often cited as a witness to scholars’ resistance to the shift from Latin to vernacular languages in the scientific literature in the early 17th century. Allegedly he was unable to read Italian, and reacted to Galileo's transition from Latin to Italian by accusing him of committing a crimen laesae humanitatis, with the double sense of “crime against humanity” and “crime against classical scholarship”. The paper shows that this claim is groundless. The arguments are as follows: 1. Kepler's alledged remark about Galileo is not documented in Kepler's works. 2. Kepler was very well able to read Italian books. 3. The expression crimen laesae humanitatis is not attested in the neo‐Latin literature of the 17th century 4. All the references of this statement can be traced back to a book by the Heidelberg professor of Romance Studies Leonardo Olschki of 1922, who did not mark the expression as a quotation and who did not give any source reference. 5. Kepler himself published scientific texts in his native German and contributed to the development of a German astronomical terminology.