ABSTRACT
In the Republic of Plato, a just, well-ordered state depends on the just, well-ordered soul of each individual. The cathedral institutes the well-ordered soul of each individual in order to facilitate a just state. The soul of each individual becomes well-ordered, through the experience of the architecture, as it ascends from the multiple particulars of experience to the universal laws which govern experience. This is enacted in the architecture through the transition from the compositions of the elevations and vaulting (Fig. 18.1), in geometrical and mathematical relations, to the purity of the light in the stained glass windows, the spiritual light, or lux spiritualis, which conveys the universal concept of the just
or the good. The mind of the viewer ascends from its material intellect, the nous pathetikos of Aristotle, which is passive and easily inuenced, to an active intellect, the nous poietikos of Aristotle, which is a universal, divine intellect. As the active or divine intellect begins to participate in the mind of the viewer through the experience of the architecture, the viewer begins to understand the concept of justice in morality, in universal truth rather than individual need or desire.
