Gustav Theodor Fechner

Gustav Theodor Fechner (German: [ˈfɛçnɐ]; 19 April 1801 – 18 November 1887) was a German physicist, philosopher, and experimental psychologist. A pioneer in experimental psychology and founder of psychophysics (techniques for measuring the mind), he inspired many 20th-century scientists and philosophers. He is also credited with demonstrating the non-linear relationship between psychological sensation and the physical intensity of a stimulus via the formula:

ln

{\displaystyle S=K\ln I}

, which became known as the Weber–Fechner law.

Early life and scientific career

Fechner was born at Groß Särchen, near Muskau, in Lower Lusatia, where his father, a maternal uncle, and his paternal grandfather were pastors. His mother, Johanna Dorothea Fechner (b. 1774), née Fischer, also came from a religious family. Some biographers consider, that despite these religious influences, Fechner became an atheist in later life, while others say that Fechner had his own religious system of belief, a synthesis of Christianity and paganism.

Fechner's father, Samuel Traugott Fischer Fechner (1765-1806) was free-thinking in many ways, such as having his children vaccinated, teaching them Latin, and being a passionate grower of fruit. He died unexpectedly in 1806, leaving the family destitute. Fechner had an elder brother, Eduard Clemens Fechner (1799-1861) and three younger sisters: Emilie, Clementine, and Mathilde. Fechner and his brother were then raised for a few years by his maternal uncle, a pastor, before being reunited with his mother and sisters in Dresden.