Friedrich Nietzsche | Friedrich Schiller | Friedrich Engels | Carl Friedrich Gauss | Karl Friedrich Schinkel | Friedrich Dürrenmatt | Friedrich Hayek | Caspar David Friedrich | Georg Wilhelm Friedrich Hegel | Friedrich Hölderlin | Friedrich Gustav Jakob Henle | Friedrich Ebert | Friedrich Wilhelm Joseph Schelling | Karl Wilhelm Friedrich Schlegel | Friedrich Gulda | Friedrich Rückert | Friedrich Paulus | Johann Friedrich Böttger | Friedrich von Huene | Friedrich List | Friedrich | Christian Heinrich Friedrich Peters | Johann Friedrich Blumenbach | Friedrich Wilhelm Freiherr von Bülow | Friedrich Specht | Friedrich Schleiermacher | Friedrich Schlegel | Friedrich Karl Dörner | Friedrich Fröbel | Friedrich de la Motte Fouqué |
With work of Friedrich Hartogs, and of Kiyoshi Oka in the 1930s, a general theory began to emerge; others working in the area at the time were Heinrich Behnke, Peter Thullen and Karl Stein.