Linear perspective

[Linear perspective] establishes … a formal separation between a subject who sees the world and the world that is seen, and in so doing it sets the stage, as it were, for that retreat or withdrawal of the self from the world which characterizes the dawn of the modern age. Ensconced behind the window the self becomes an observing subject, a spectator, as against a world which becomes a spectacle, an object of vision.” (Romanyshyn, p42)