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.
Władysław Witwicki
Władysław Witwicki (30 April 1878, Lubaczów – 21 December 1948, Konstancin) was a Polish psychologist, philosopher, translator, historian (of philosophy and art) and artist. Seen as one of the fathers of psychology in Poland. He studied at the University of Lwów and became a professor at the University of Warsaw.