UC Riverside

Guarino Guarini's dome of San Lorenzo in Turin is singular. There are three predominate features that make it so: first, the pattern of the exposed ribs; second, the radical opening of the webbing between the ribs; and third, the conceit that it is not fully supported by the structure below it. While scholars have long questioned the reasoning behind the domes appearance, the impetus for its creation has not been fully addressed.

After noting a radical alteration in Guarini's architectural designs during his time in Paris, I explore the intellectual discourses of the city during this period. One such conversation in particular may account for these changes — the discussion surrounding the antique manuscript On the sublime attributed to Longinus. By comparing this manuscript with Guarini's Architettura civile and San Lorenzo, I demonstrate how Guarini thought about architecture in terms that are very similar to the way Longinus explains the sublime. Then, by addressing the design of San Lorenzo as a vehicle of persuasion for both the Savoy and the Teatine Order, a very strong motivation to use Longinus' manuscript for the composition of the church emerges.

Another important observation included in this exploration is a new alternative approach to the reading of the iconography of the dome. I point out a similarity between the design of the dome of San Lorenzo and an unexecuted window for the Chapel of the Holy Shroud. I propose that both of these designs represent a passionflower — a symbol of Christ's passion and a popular meditative symbol in theological literature of the period. The passion of Christ is also the significance of the relic of both San Lorenzo and the Chapel of the Holy Shroud — the Holy Shroud itself, the most important relic held by the Savoy family and used to confirm its pretensions to a royal title. Therefore, the passionflower symbol served both the needs of the Theatine Order and the Savoy family.