Gustav T. Fechner
1801 - 1887
Gustav Theodor Fechner, (born April 19, 1801, Gross Särchen, near Muskau, Lusatia [Germany]—died Nov. 18, 1887, Leipzig, Ger.), German physicist and philosopher who was a key figure in the founding of psychophysics, the science concerned with quantitative relations between sensations and the stimuli producing them.