Étienne Bonnot de Condillac was one of the French philosophes, known primarily for his development of the doctrine of "sensationism." According to this doctrine, not only all of one's thoughts but even the basic operations on these thoughts derive from sensation.

Condillac was born on September 30, 1714, in Grenoble, one of five children of Gabriel Bonnot, vicomte de Mably, and Catherine de la Coste. He took the name of Condillac after his father purchased an estate of that same name in 1720. Condillac was born with poor eyesight that prevented him from reading before the age of twelve, and he was considered in his childhood to possess only limited intellectual abilities. However, in 1730 he took up residence with his brother, the abbé de Mably, in Lyon to attend the Jesuit college there, and in 1733 he went to Paris...