Théodule-Armand Ribot (18 December 1839 – 9 December 1916) was a French psychologist. He was born at Guingamp, and was educated at the Lycée de St Brieuc. He is known as the founder of scientific psychology in France, and gave his name to Ribot's Law regarding retrograde amnesia .
A philosophical disciple of Hippolyte Taine and Herbert Spencer (whose Principles of Psychology he translated), Ribot, with Taine, initiated the study in France of a positivistic and physiologically oriented psychology. His interest in philosophy was inseparable from his interest in concrete psychological problems and persisted throughout his life.
The centenary of Ribot’s passing is thus a unique occasion to honor him as one of the great figures of psychology. Not only did he play a major role in the development of psychology in France, but he also became a major international figure of psychology at the turn of the 20th century.
Ribot was among the first to study dissociations of personality, and his law of regression — that amnesia affects the most recent and least organized impressions and reactions first — was a lasting contribution to psychology.