One unmistakable thread of 18th century France is the possibility of change, particularly in one's own identity, as a rising middle class redefines a centuries old strict relationship between upper and lower classes, changing the meaning of social roles, of titles, and even of physical space as a new social and architectural reality takes root. (This claim is no doubt much more meaningful for white males of that era.) Given that the century is building to a tumultuous change and the introduction of the modern era of world history, our study of art does have to be grounded in this history, meaning the rise of a middle class and the setting of the stage for the violent end of a rigid social order.
While the previous era's neoclassical theatrical art is didactic, formulaic, and focused on grandiose, unmistakable spectacle, beginning with Voltaire's agitation for laxer rules there is an increasing freedom to move in new directions. The work of Denis Diderot illustrates a shift into a new space, the family living room, even though he will continue in the footsteps of the Neoclassicists by using theater as a vehicle to present absolute truths to audiences in a didactic way.
This freedom of identity is a conundrum for essentialists, and its most obvious expression is in the theater where an actor takes multiple roles on a nightly basis. Diderot again explores this problem in his analysis of what it means to be an effective actor, simultaneously expounding a belief in platonic ideals while insisting that an actor can through their body, their external frame, adopt and present any of these idealized forms, in this way presenting Truth with a capital V (for Verité). Despite reflecting the spirit of the age, this is an anxiety inducing claim to some: to quote Ankersmit, "Rousseau argues that the theatre may threaten our moral integrity since we may forget who we really are when confronted with a pseudo-reality consisting of representation only." (324)
As for what we will leave out: since Diderot has his fingers in so many rich pies we have to leave out anything he didn't touch. Most of Europe falls under this list, as we narrow our study to Diderot's La Père de Famille and to the changing social and political reality of pre-revolutionary France.
Ankersmit, Frank R. "Pygmalion: Rousseau and Diderot on the theatre and on representation." Rethinking History. 7.3 (2003): 315-339. Web.
Diderot, Denis. The Paradox of Acting. Trans. Walter Herries Pollock. London: Chatto & Windus, 1883. Web.