Diderot outlines the question of maturity in many places of his works. He intends maturity as emancipation of the individual and of the people. Only with an education to strengthen the autonomous use of reason, this process of self-improvement could be successful. However maturity is also interpreted like a happy moment during the life, among youth and oldness, when the subject finds the right balance between imagination and reason, poetry and philosophy. A similar dynamic characterizes the people and their artistic productions. The effort of Diderot is to contribute to the emancipation of people by the diffusion of Enlightenment with the Encyclopédie, with plans for public instruction, but especially by theorisation and composition of Bourgeois’ dramas.