Answer
**Empiricism**, championed by Gustav Fechner, holds that all knowledge is derived from experience and observation. It emphasizes the role of sensory experiences in acquiring knowledge and understanding the world. Empiricism stands in contrast to rationalism, which emphasizes the role of reason and innate ideas. Fechner's contributions to empiricism include his psychophysical experiments that established a quantitative relationship between physical stimuli and subjective experiences, advancing the scientific study of psychology.