The Desire to Ascend.  The Gothic cathedral makes us long to climb.  Approaching from afar we marvel at the great height of the edifice and tantalizing glimpses of upper passages and the viewing chambers in the steeple.  Inside, as we gaze upwards we may wonder about that mysterious dusky passage half way up the elevation: the triforium.  Surely, the mysteries of the cathedral would reveal themselves more clearly from such a height....  We share this anticipation of the affective power of great height with our predecessors, medieval pilgrims: "for indeed, whoever visits the spaces of the gallery, if he goes up sad, after having seen the perfect beauty of this temple, he will be made happy and joyful" (The Pilgrim's Guide to Santiago).

There are six spiral staircases set into the thickness of the outer buttresses: we will climb via the south transept where the staircase is accessible from the chapel dedicated to the Conversion of Saint Paul.  We enter into the dark confines and toil up the steep winding staircase.  Passage into the triforium of the south transept brings a burst of light and vision (use the panorama for a stunning vista) allowing us to share something of Saint Paul's recovery of sight after his transformative experience on the road to Damascus.  There are three dimensions to this new vision.  First, a powerful response to the stunning precariousness and beauty of the space, with its clear lines, delicately sculpted details and heavenly luminosity.  Precariousness is experienced in the combination of the fear of heights and the inexplicable urge to lurch forward into space.  And the stones of the transept arcade bear witness to alarming movement and deformation: you can see the gaping cracks in the masonry of each of the 4 bays adjacent to the crossing.  The iron chain installed to arrest this movement runs at our feet in the triforium.  Second, we may wonder whether the use of simple geometrical building blocks enhances the beauty of the place inducing a sense of well-being resulting from the fact that we are exactly half way up the elevation: orthogonal lines no longer converge.  The overall transverse section is set in a great square; the space of the aisle and central vessel is established by piling three squares one atop the other.  And third, the experience of the upper parts of the cathedral leads to an enhanced awareness of the identity of the two architects who built the upper nave and the upper choir.  Use the panorama in the upper south transept to look at the dark triforium in the upper nave and west side of the transept and the glazed triforium in the eastern upper transept and choir.  This is the work of father and son: Thomas and Renaud de Cormont.  You may then follow the tour around the upper building, becoming familiar with the reassuringly solid architectural forms created by master Thomas in the upper nave (massive flying buttresses; lean-to roof over the aisle) and the contrasting flimsiness of Renaud's work (openwork flyers and glazed triforium necessitating a shallow-pitched roof).