Breaking rules and squeezing pediments: San Carlo alle Quattro Fontane

by Agnes Crawford

I have recently been in something of a Baroque phase, as my previous posts on the Gesù, and this piece at arttrav on Sant’ Andrea al Quirinale suggest. Just a stone’s throw from Sant’Andrea, is San Carlo alle Quattro Fontane, one of my favourite Roman churches. It is the great masterpiece of Bernini’s contemporary and often thwarted rival, Francesco Borromini. These two churches, like the men themselves, are both incredibly different and yet both inescapably the product of seventeenth century Rome.

Francesco Castello was born in 1599 at Bissone on Lake Lugano, in modern-day Switzerland. His was a family of stonemasons, and relatives included the illustrious Domenico Fontana and Carlo Maderno, both successfully in practice in Rome. Francesco took his mother’s family name, perhaps with the intention of recalling the noble Borromeo family.

In 1619, aged twenty, Borromini moved to Rome where his career was to be thwarted on a number of occasions by the vicissitudes of patrons and economics, and by the architect’s somewhat garrulous temperament. While Bernini was gregarious, the father of a large family, master to a large workshop, friend to princes and popes, Borromini was tormented and solitary. While Bernini’s long career was, with one notable blip, prolific and successful, even seeing him styled Cavaliere, Borromini’s was fraught with disappointment and pitfalls. In 1667, at the age of 68, Borromini committed suicide.

Francesco Borromini 1599-1667

The crowning glory of his career, and the first of his solo commissions, is undoubtedly the tiny complex of San Carlo alle Quattro Fontane. The church is dedicated to St Charles Borromeo, the former Archbishop of Milan who had died ten years before Borromini’s birth, and who had been a lynchpin of the Council of Trent. In 1634 aged thirty-five, a relatively advanced age for a first commission, Borromini was commissioned to create a cloister, living quarters, and church for the order of Discalced Trinitarians, whose main objective was the raising of funds to liberate Christians captured by the Moors. When Borromini came to the project it had already been over twenty years since the Trinitarians had acquired the small and awkward site on the corner of the Via Pia (now the Via XX Settembre) and the Via Felice (now the Via delle Quattro Fontane), and the initial interest in funding the project expressed by Francesco Barberini, whose palace was on the other side of the Quattro Fontane, had come to nothing. Such is the tiny scale of the church that it is popularly known by the diminutive “San Carlino”.

A view of San Carlo in an 18th century engraving

The introduction of Borromini’s treatise on architecture, Opus architectonicum, published by his patron Virgilio Spada tells us, in very long sentences, that he had to remind the Order when

“it seems to them that I move away from conventional designs, of Michelangelo, Prince among Architects, who said that he who follows others never overtakes them, and I certainly would not have joined this profession with the intention of being a mere copyist, even though I know that the invention of new things does not reap the fruits of the labour, if not late, given that the same Michelangelo did not receive it when in reforming the architecture of the great Basilica of St Peter he was attacked for new forms and ornamentations…”.

These “new things” saw him much criticized as an architect who ignored the rules of the Ancients in favour of whimsy. However it is his clear knowledge of those rules, and the facility and ingenuity with which he manipulated them, which has ensured his reputation as one of the great geniuses in the history of architecture.

The ‘rules’ referred to here are those laid down by Vitruvius. Architect to Augustus, he wrote the “Ten Books of Architecture”. Transcribed throughout the Middle Ages, most notably at the court of Charlemagne at Aachen, they form the bedrock of the studies of Renaissance architects. Central to Vitruvius’ ‘rules’ is the study and emulation of the proportions and forms of nature. He is most celebrated for his assertions that the proportions of the human body should be the basis of architectural design. Today this theory is best known through the drawing of “Vitruvian Man” by Leonardo da Vinci.

Vitruvian Man, Leonardo da Vinci

In Book I, Vitruvius tells us that architecture is made up of ordinatio (the use of the correct scale of the various parts of the building); dispositio (how the various elements are put together); eurythmia (the harmonious relationship between the height and width of the various parts of the building); symmetria (the harmonious relationship between the various elements of the building, and the relationship between the individual parts and the overall whole); decor; and distribution (the clear balance of resources and space available).

He also mentions the importance of innovation, saying that: “innovation is the resolution of difficult problems and the intelligent discovery of new things”.

Vitruvius also tells us that architecture must be governed by the principles of firmitas, utilitas, and venustas (stability, functionality, and beauty).

His is a practical manual, less interested in the abstract than in the practicalities of building. He speaks of the economic concerns of building projects (use readily available local materials wherever possible – Book I), of the effect of climate on the human body (warm temperatures facilitate the mind, whilst cold encourages laziness – Book VI), and gives instructions on a multitude of building types; temples and theatres, bath complexes and houses.

In fact, Borromini’s critics were wrong. At San Carlo he demonstrates great invention in maximising the potential of an extremely difficult site, and the firmitas, utilitas, and venustas of his project are beyond doubt. His is a plan which does not ignore the rules of the Ancients, but rather than simply echoing their forms goes deeper to assimilate their fundamental principles. He produced an architecture which depends absolutely on the knowledge of what has been called the “classical language of architecture”.

Indeed he proudly states in Opus architectonicum that he “imitated the ancients rather than the moderns”. Despite this assertion, Borromini’s work can nevertheless be seen also to depend on the manipulations of this ‘classical language’ which had characterised the later part of Michelangelo’s architectural career.

Borromini owned a copy of Pirro Ligorio’s Antichità di Roma, and probably knew of Ligorio’s reconstructions of Hadrian’s Villa. Many of Ligorio’s drawings feature the concave and convex forms which we see in Borromini’s work. Most notable among these is the Piazza d’Oro.

Reconstructed floorplan of the Piazza d'Oro at Hadrian's Villa featuring convex and concave forms, especially at the right.

So we can say that Borromini’s work is neither entirely a complete reworking of the ‘classical language’, but nor is it a simple parroting of classical forms. Rather it is something more complex. The criticisms against Borromini depend on the fact that the architecture of the sixteenth century had relied almost exclusively on the study of Vitruvius. Writing at the birth of the Roman Empire for its first Emperor, Vitruvius was notoriously conservative, refusing even to acknowledge the Tuscan and Composite orders developed by the Romans in favour of the Greek orders. It is this selective view of the Antique, and buildings which illustrate it – dominated of course by the Pantheon – which was studied by Bramante and his followers. However this was a very limited view of Antique Roman architecture, and ignored much of the elaborate forms of later Imperial buildings. Amongst these we might include Hadrian’s villa, the Baths of Diocletian, and the whimsical nymphaea which decorated the gardens of country houses. Elaborate Imperial era buildings with concave and convex forms which are strikingly similar to Borromini’s work have been discovered in the Eastern Empire, preserved in the sands at Petra in Jordan and at Leptis Magna in Libya.

The "treasury" at Petra

There is no suggestion that Borromini knew these examples, but the architectural features of the provinces of the Empire quite plausibly had their counterparts in Rome, perhaps amongst the elaborate tombs which once lined the Appian Way, many more of which were intact during Borromini’s lifetime. It is also worth noting that these Late Imperial forms, like the Pantheon, are fundamentally Roman, the result of materials and techniques unknown to the Greeks; in particular the development of concrete, and the infinite variety of forms it made possible.

It is therefore plausible to say that Borromini took as his point of departure the elaborate forms of the later Imperial period, as represented in the sixteenth century reconstructions of figures such as Pirro Ligorio. He emulated and developed the interplay of curve and shadow he may have found in certain monuments. Together with these forms he manipulates elements of the ‘classical language’ to subvert its solid logic and create an architecture which captures both the underlying religious mood and spirituality of seventeenth century Rome, and indeed his own torment.

If we continue to consider Vitruvius’ principles, we can say that at San Carlo Borromini undoubtedly creates a work of utilitas and venustas. However, whilst the building’s stability is not in question, he undermines the expression of this firmitas in its architectural features.

Entering the church from the via del Quirinale, we are confronted with a flow of curves which give the interior a sense of fluidity. The undulation of shallow bays into deeper ones is emphasized by the straight elements that link them.

Floorplan of the church

Columns set into the walls serve as ‘commas’ between the various elements, guiding the eye around the space. Running above the columns, is the horizontal entablature. Four half domes rise above the curved bays. So far, so classical. However within each of these coffered domes, is a pediment which is an initial indication that all is not as it should be. It is not quite wide enough for the space, its oddness is further emphasized by the very slight concavity of the two diagonals. It is as if an external force is pressing down upon it, emphasized by the coffers which get larger as one looks upwards. It would have had Vitruvius and Bramante turning in their graves.

Squashed pediment within the half dome with its perspective-defying coffers.

Looking up we see an oval dome perching upon the arches of the four half domes. The oval is a shape which Vitruvius and his Renaissance disciples would have despised for its absence of clarity; whilst the circle, like the square, leaves us in no doubt of the proportions, an oval has no fixed proportion between its short and long axes. Above, the dome culminates in the lantern in which a curious irregular octagonal with concave sides bears a dove within the triangle of the Trinitarians. The dome is coffered with various shapes – crosses (one of the symbols of the Trinitarian order), octagons and hexagons – which diminish in size as they near the lantern.

View of dome

With the use of the oval, the shallow curves of the bays, and the squashed short pediments, Borromini denies us what the architects of the Early and High Renaissance sought above all in their studies of Vitruvius; the logical expression of the structure of a building in its decoration in which the proportions of the smallest element can lead us to the proportions of the whole structure. This is perhaps best expressed in the Pantheon, studied by them as the great paradigm of the architecture of the Antique; famously the dome of the Pantheon is a perfect hemisphere, its diameter identical to the greatest height of the building. When ovals are introduced, or when pediments are squashed and do not reach the top of the arch we are denied this understanding of the space we occupy. It is this deliberate manipulation of the familiar to create the unfamiliar which is behind the unsettling architecture which Borromini creates, and which is so expressive of the state of flux of the Roman Church, and hence the city, in the seventeeth century.

The distance between the top of the pediment and the base of the dome is not definable in relation to any of the elements, and is therefore insurmountable.

The church can thus be seen to be made up of three distinct levels. The lowest is the level we experience directly as a visitor, which we can see to represent all things earthly. The uppermost is the dome, its apparent jumble of curiously shaped coffers rising dizzily towards the dove, the representation of the divine. The problem is the middle level, how does one rise from the earthly to the divine? One needs to pass the level of the half domes, however they do not obey any of the rational laws we have been taught. If the High Renaissance taught that the heavenly was governed by order and logic, and that mankind was able to comprehend the incomprehensible, in the seventeenth century the art of the Baroque tells us that the transition from the earthly to the divine is altogether more uncertain. It is beyond the realm of the knowable, disobedient to the laws of matter.

San Carlo alle Quattro Fontane, via del Quirinale 23. Open: Monday-Friday 10am-1pm, 3pm-6pm; Saturday 10am-1pm;Sunday noon-1pm (Mass at 11am)