Gustav Fechner

Gustav Theodor Fechner was a German physicist, philosopher and experimental psychologist, born in 1801 near Muskau in Lower Lusatia and active in Leipzig for most of his life. He earned his doctorate at Leipzig in 1823 and became professor of physics there in 1834. After an eye injury caused by his research on afterimages he turned to the relation between mind and body. He founded psychophysics, techniques for measuring the mind, and is credited with showing a non-linear relationship between the physical intensity of a stimulus and the sensation it produces, known as the Weber-Fechner law. His Elements of Psychophysics appeared in 1860, and the International Society for Psychophysics holds its annual conference on Fechner Day. He died in 1887.