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.
Psychology
In the 1950s and 1960s, influenced by philosophers Søren Kierkegaard and Martin Heidegger and, psychoanalytically trained American psychologist Rollo May pioneered an existential branch of psychology, which included existential psychotherapy: a method based on the belief that inner conflict within a person is due to that individual's confrontation with the givens of existence. Swiss psychoanalyst Ludwig Binswanger and American psychologist George Kelly may also be said to belong to the existential school. Existential psychologists differed from more "humanistic" psychologists in their relatively neutral view of human nature and their relatively positive assessment of anxiety. Existential psychologists emphasized the humanistic themes of death, free will, and meaning, suggesting that meaning can be shaped by myths, or narrative patterns, and that it can be encouraged by an acceptance of the free will requisite to an authentic, albeit often anxious, regard for death and other future prospects.