Gustav Fechner
Fechner, along with Wilhelm Wundt and Hermann von Helmholtz, is recognized as one of the founders of modern experimental psychology. His clearest contribution was the demonstration that because the mind was susceptible to measurement and mathematical treatment, psychology had the potential to become a quantified science. Theorists such as Immanuel Kant had long stated that this was impossible, and that therefore, a science of psychology was also impossible.
Albert Moll (German psychiatrist)
Albert Moll (; 4 May 1862, Lissa – 23 September 1939, Berlin) was a German psychiatrist and, together with Iwan Bloch and Magnus Hirschfeld, the founder of modern sexology. Moll believed sexual nature involved two entirely distinct parts: sexual stimulation and sexual attraction.