Leopold von Ranke (German: [fɔn ˈʁaŋkə]; 21 December 1795 – 23 May 1886) was a German historian and a founder of modern source-based history.[3][4] According to Caroline Hoefferle, "Ranke was probably the most important historian to shape [the] historical profession as it emerged in Europe and the United States in the late 19th century".[5] He was able to implement the seminar teaching method in his classroom and focused on archival research and the analysis of historical documents. Building on the methods of the Göttingen School of History,[6] he was the first to establish a historical seminar. Ranke set the standards for much of later historical writing, introducing such ideas as reliance on primary sources (empiricism), an emphasis on narrative history and especially international politics (Außenpolitik). Ranke also had a great influence on Western historiography. He was ennobled in 1865, with the addition of a "von" to his name.

Thus have been briefly noticed the results obtained by research in the Leipsic laboratory during the past seven years. They prove conclusively that it is possible to apply experimental methods to the study of mind. The positive results are, besides, not insignificant, and will compare favourably with what has been accomplished during the same period in many chemical, physical and physiological laboratories. An increased interest is everywhere being taken in experimental psychology, and we may hope that we shall some day have as accurate and complete knowledge of mind as of the physical world.