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.
Søren Kierkegaard
Kierkegaard had a profound influence on psychology. He is widely regarded as the founder of Christian psychology and of existential psychology and therapy. Existentialist (often called "humanistic") psychologists and therapists include Ludwig Binswanger, Viktor Frankl, Erich Fromm, Carl Rogers, and Rollo May. May based his "The Meaning of Anxiety" on Kierkegaard's "The Concept of Anxiety". Kierkegaard's sociological work "Two Ages: The Age of Revolution and the Present Age" critiques modernity. Ernest Becker based his 1974 Pulitzer Prize book, "The Denial of Death", on the writings of Kierkegaard, Freud and Otto Rank. Kierkegaard is also seen as an important precursor of postmodernism. Danish priest Johannes Møllehave has lectured about Kierkegaard. In popular culture, he was the subject of serious television and radio programmes; in 1984, a six-part documentary presented by Don Cupitt featured an episode on Kierkegaard, while on Maundy Thursday in 2008, Kierkegaard was the subject of discussion of the BBC Radio 4 programme presented by Melvyn Bragg, "In Our Time", during which it was suggested that Kierkegaard straddles the analytic/continental divide. Google honoured him with a Google Doodle on his 200th anniversary.