Unless we are to condemn all modern painting, we must regard cubism as legitimate, for it continues modern methods, and we should see in it the only … - Jean Metzinger

Whether it is Juan Gris taking objects apart, Picasso replacing them with objects of his own invention, or another who replaces conical perspective by a system based on the relations between perpendiculars, all that only goes to show that Cubism was not at all born out of an authoritative theory [mot d'ordre]; that it only marked among a few painters the will to be finished with an art that never ought to have survived the condemnation pronounced upon it by Pascal.

To understand Paul 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.

If we wished to relate the space of the [Cubist] painters to geometry, we should have to refer it to the non-Euclidean mathematicians; we should have to study, at some length, certain of Riemann's theorems.