While Charles Bonnet's psychology has often been approached solely from the perspective of the history of ideas, this article proposes a social and cognitive history approach to psychology. It shows how, in the 1740s, Bonnet shifted from his identity as a naturalist to that of a philosopher and psychologist in a European context of changing sensibilities toward psychology and philosophy, turning toward empiricism and even materialism. With the help of a network of friends, Bonnet fought against a double handicap - he was partially blind and partially deaf - to develop his psychology and to become part of the Geneva social scene. In particular, he joined several societies whose members used to read works on science, morality, and philosophy, creating a welcome network for the new ideas of the Enlightenment. One of these societies, the Société des 4 B - whose members' names began with the letter B - was founded in the middle of the century and served for a decade as a specific context of discursive confrontation for many of Bonnet's later ideas and texts. It was during this period that he published his most important psychological texts.