Brother of the Mably abbot, ordered priest himself in 1740, it was, of 1758 to 1767, tutor of Ferdinand of Parma. Friend of certain encyclopedists (Diderot, Rousseau), it was allured by the ideas of Locke and Newton, and undertook a descriptive analysis of the understanding, based on only one principle allowing a rigorous “recombining” of the unit (the myth of the “statue”). Thus, in its Treaty of the feelings (1754), he wanted to show that all our ideas come from the feelings: the touch, paramount direction, the language, sign essential (“science is a language well done”), constitute the pivots of a logic and an inciting psychology, constantly called upon and criticized thereafter (Test on the origin of human knowledge, 1746). (French Academy, 1768).

“The Test on the origin of human knowledge”, published in 1746, contributes notably to the diffusion of the ideas of Locke among the thinkers of the XVIII E French century, and registers the question of the language in the middle of the empiricist theories of knowledge. The Treaty of the systems, which appears in 1749, provides the independent source of the criticism of great traditional metaphysics. In 1754, the Treaty of the feelings describes the operation of the judgment and the acquisition of knowledge starting from the fiction of a statue which would be gradually provided with the various directions. And the Treaty of the animals that Condillac produces in 1755 brings new elements in the traditional discussion on the heart of the animals.

All these points are discussed in work of Rousseau, which meets Condillac in Lyon in 1741, in his/her brother Jean Bonnot de Mably. However, the evolution of the abbot towards a form of sensualism leads the author of the Profession of faith of the Savoyard Vicar to criticize several theses condillacians. Rousseau refuses to consider that the judgment is only one transformed feeling: according to the Vicar, it is necessary to distinguish an active ingredient in any comparison from reports. The instinct of the animals is not, as claims it Condillac, the product of a practice but an innate provision. The mention of Condillac in the Speech on the origin of the inequality attests moreover the importance of its philosophy of the language, whose Rousseau will criticize the starting point in the Test on the origin of the languages. Condillac died close to Orleans in 1780.

More, consult the card on Étienne Bonnot de Condillac.