To understand Cézanne is to foresee Cubism. Henceforth we are justified in saying that between this school and previous manifestations there is only a difference of intensity, and that in order to assure ourselves of this we have only to study the methods of this realism, which, departing from the superficial reality of Courbet, plunges with Cézanne into profound reality, growing luminous as it forces the unknowable to retreat.