ST PETER'S IN
From the book "St.
Peter's in the Vatican," edited by William Tronzo, ©
Cambridge University Press 2005
BERNINI AT ST. PETER'S
Singularis in Singulis, in Omnibus Unicus
Two contemporaneous projects envisioned by Bernini under Urban VIII began the gigantic task of articulating the longitudinal axis defined by the apse and nave. In doing so, Bernini treated he crossing and the nave as the intersection of two complementary functions, not only of church architecture but of the house of God itself, as a locus of memory and as a place of action. The papal tombs in the apse represent the "sequel" to the crossing's commemoration of Christ's sacrifice and the building of his church on the cornerstone of St Peter. The nave takes up the theme announced in the apse: history in action.
"FEED MY SHEEP" (1633-46)
The story begins, literally as well as figuratively, in the atrium above the main portal to the basilica, with a grandiose relief depicting the venerable theme of Pasce oves meas, "Feed My Sheep" (Fig. 151). The Gospel of John records that in a postmortem appearance to his disciples as the Good Shepherd, Christ assigned to Peer the task of nurturing his mystical flock. The episode was universally interpreted as the institution of the Church with Peter and his successors at its head.58 The work thus illustrates the historical and divine sanction for Christianity and the authority of the popes. Bernini perceived the underlying paradox of this epochal theme, an august condescension of absolute power, in a context of a pastoral meekness and gentility. Both these qualities are conveyed by the "historicizing" style that recalls the venerable antiquity of the event and endows it with the visual authority of classical art. The subject is cast in a lyrical, idealizing mode that suggests the Augustan pastoral poetry of Christ's own time, notable the Georgics of Virgil. This classical tradition, to which Urban's own "Pindaric" poetry on sacred themes belonged, was deeply imbued with the idea of the perennially returning Golden Age. Church history thus begins and is perpetuated here, in the verdant landscape of an idyllic time and place - past, present and future - at the entrance to St Peter's.
Bernini's presentation imparts a twofold message concerning the import of the scene. On the one hand, Christ displays his august authority in the ideal perfection of his human form and the noble grace of his dual action; he faces Peter to establish his primacy among the apostles as Christ's chosen spiritual heir, while gesturing behind to convey his authority over - and responsibility for - his flock. On the other hand, the composition also emphasizes the humility and obedience of Peter, who kneels in an attitude of devoted self-abnegation. In the gospel account, Peter affirms three times his love for Christ - who thrice affirms his charge, "Feed my sheep" - in penitential atonement for Peter's threefold denial of the Lord at the time of the Passion. Peter's supreme office is thus linked to his humble devotion, and to Christ's forgiveness of the first penitent.
The supreme, divinely ordained hegemony of the church and the papacy in the terrestrial realm is the theme of another "historical" work commissioned by Urban VIII at the same time, in the nave of the basilica. Following the initial foundations by Constantine the Great and his mother, there was another heroic instance in which secular rulers acknowledged the superior authority of the papacy and greatly augmented the church's earthly patrimony. Urban's eleventh-century compatriot, Countess Matilda of Tuscany, had been a staunch supporter of the papacy in its manifold and prolonged power struggle with the Holy Roman Emperor and donated to the Church her vast territories in south Italy. As he had appropriated for the crossing pier the relics of the passion from S. Croce in Gerusalemme, Urban removed Matilda's body from its original resting place in Lombardy for reburial in a tomb in a niche in the north side aisle (Fig. 152). History is here portrayed metaphorically, for there is nothing medieval about the figure of the countess. Bernini represented her instead as a grandly regal Roman matron in a purely white environment clearly intended to suggest an ancient commemorative monument. In form as well as content, the figure establishes a link between the empress Helen, with her attributes changed from the instruments of the Passion to Matilda's military command baton and the tiara and keys of the papacy, and the commanding Christ of the "Feed My Sheep."59 Matilda is thus presented as the ideal companion of the original secular founders of the church.
The simple trapezoidal coffin (Fig. 153) suggests ancient frieze sarcophagi, especially, and appropriately, the Etruscan sarcophagi of Tuscany. The relief celebrates Matilda's role in a signal victory of the papacy in the contest with the emperors over investiture, the right to nominate abbots and bishops. Henry IV is shown in abject prostration receiving the forgiveness of Gregory VII at Matilda's castle at Canossa, thus acknowledging the superior authority of the papacy in the matter of investiture. The emperor's claim was in direct contradiction to the meaning of Pasce oves meas as understood by the papacy. The composition of the relief scene strikes an inescapable analogy with the penitential obeisance of Peter and the pontifical forgiveness by Christ as depicted over the entrance. The conflict between secular and ecclesiastical authority persisted in Urban VIII's time, and the work was surely intended to set an example to the current rulers of Christian Europe. This contemporary significance is made evident by the features of Gregory VII, which are those of Urban himself. Bernini declared visually that this is a commemorative monument as well as a tomb, by placing on the lid of the sarcophagus an inscribed cartouche held up like a billboard by two kneeling putti. The inscription describes Matilda not simply as a donor but as a woman of male spirit, protector (propugnatix) of the Holy See; she wears an armored breastplate and carries a military commander's baton in allusion to the fact that she actually led her troops in defense of the papacy.
Most extraordinary, Bernini inserted the sculpture in a double niche, the outer shell of which consists of panels that diminish in perspective toward a vanishing point at the center of the figure. Physically, the double niche allowed Bernini to include the whole monument in the narrow, shallow space available. The outer shell functions visually in two ways. The perspectivized coffering acts as a visual loudspeaker, magnifying the figure as it thrusts forward from the inner niche into the space of the spectator. At the same time, the expanded outer shell gives a wider "arc of visibility" within the restricted confines of the aisle. This ideal, antiquarian commemoration of a distant past is cast into an immediate, celebratory present by a pair of airborne putti who complete the monument by assembling the countess's coat of arms at the apex of the arch.
Early in the reign of Urban's successor, the Pamphili pope Innocent X, the concept of devoting the longitudinal axis of the basilica to the history of the Church came to fruition. The importance attached to the theme is indeed evidenced by the fact that it was retained and developed despite the new pope's bitter hatred for his predecessor and his equally hostile attitude, at least initially, toward Bernini. To illustrate this history, an extraordinary coincidence of form and content was worked out for decorating the nave piers that gave the church a new sense of direction. For the elaborate but mute abstract designs of flat, multicolored marble incrustation with which the surfaces had been reveted before the nave was built, Bernini substituted a simple, articulate, sculptured voice (Fig 154; earlier revetment visible at far right).
The point of departure was one of the most important of all documents concerning the history of St Peter's and its decoration, a letter composed at the end of the thirteenth century by one of the church's greatest patrons, Nicholas III (1277-80). What has been called the Magna Carta for the canons of St Peter's is a letter Nicholas wrote urging them, among other reforms, to look to the condition of their church to assure that its physical state was worthy of its exalted spiritual status: "The Church Militant can be visualized as the holy city of the New Jerusalem, descending from heaven and prepared by God as a bride adorned for her spouse." Conceived as the Heavenly Jerusalem, the church was to be appropriately arrayed. Under Nicholas, the adornment took the form of a series of medallions of the popes aligned along the clerestory wall. Representing the popes in this manner was, in fact, a cooptation of a much earlier system of church decoration in which medallion portraits of saints populated the celestial hierarchy represented by the building itself, except that earlier the medallions were generally confined to subsidiary locations in borderline friezes. Under Nicholas the papal portraits occupied a conspicuous part of the basilica's main field of decoration. And in the papal series the idea of a temporal sequence provided the sense of continuity and perdurance that was essential to the meaning of the frescoes. Recreating the program in the new nave was, it might be said, a double confirmation of the idea of continuity, in the sequence of popes and between the old basilica and the new.
The new version comprised several fundamental changes, in content as well as form. Most significant, perhaps, is that not all popes were included, only those who were sainted.60 There was thus a reversion and convergence with the early tradition of medallion saints, as if to populate the Heavenly Jerusalem with its principal denizens from the church hierarchy. Second, the portraits are not arranged in a line, but in zigzag fashion back and forth across the nave. The disposition was clearly adopted from that of the series of standing papal portraits in the Sistine Chapel, where this serpentine organization serves to interlace and bind together the Old and New Testament narrative cycles running parallel along the chapel walls.61 The Sistine Chapel is where the popes are elected, where the divinely ordained succession is perpetually renewed. Moreover, the medallions were not shown in isolation but as if born aloft, along with the papal tiara and keys, by pairs of winged putti. The "imago clipeata," as this motif was called, was the ancient method illustrating the triumph of the soul and apotheosis, in this case clearly the saintliness of those portrayed.62 And finally, Bernini's medallions are sculpted, not painted, so that they partake of a different level of reality. With gilded backgrounds and set against the polychrome marble pilaster surfaces, the white marble reliefs appear as real objects suspended in space, where they serve as animated memory messages miraculously transported from the past to the present. The nave fairly pulsates with the persistent rhythm and energy of their reminders.
In the spandrels of the arches huge female personifications of the virtues recline on the arches of the nave arcade (Fig 155). They, too, make clear reference to antiquity, assimilating the analogous figures of Victory that were commonly placed in the spandrels of Roman triumphal arches. Through their reference to pagan triumphal imagery, the allegories emphasize that the victory of the Church was theological and moral, not military. Pervaded with the emblem of Innocent X, a dove with an olive branch in its beak, the traditional symbol of peace, the entire decorative system calls on the language of classical antiquity to express historically the divinely ordained, pacific triumph of Christianity.
The organization also suggests a progression reciprocal to our ordinary perception of the relationship between the nave and the crossing, from the entrance to the high altar. This transition from the mundane to the spiritual world is indeed the practical experience of the visitor; but for the believer, the direction of spiritual movement is exactly the opposite. As the dove of the Holy Spirit under the canopy of Bernini's Baldacchino sheds its light down upon the sacrament at the high altar, so its grace radiates outward from that epicenter to illuminate the world. Thus, once again, and most important, the Early Christian basilica is recalled: from earliest Christian times the movement, in theological and in decorative terms, was always from the altar outward to the entrance of the church.63
THE PIAZZA AND COLONNADES
The same outward orientation drove the designs of the piazza and colonnades in front of the church and the Cathedra Petri in the extremity of the apse. These mighty projects commissioned by Bernini's friend and multifarious Maecenas, Alexander VII, brought to completion and closure the longitudinal extension of the basilica. One of the fundamental concepts of Christianity, derived from the mystery religions of antiquity, was that of initiation, the process whereby neophytes, or catechumens, would "prepare" to enter the church proper. From the very beginning of church architecture this idea of a preliminary "foreclosure" was translated into an atrium or forecourt preceding the entrance to the building. At St Peter's, the forecourt as a reception and gathering place for devotees was combined with another function that had developed relatively recently in the history of the church. From the beginning of the thirteenth century, there had been a phenomenal increase in devotion to the central mystery of the Eucharist. The devotion was greatly augmented in response to the attacks of Protestants on what they perceived as the theological and institutional trappings with which the Church had encumbered the simple facts of belief and grace. Such factors had led at St Peter's to the development of the greatest annual "urban" devotion of the church calendar, the procession of Corpus Domini: the pope, displaying a monstrance containing the Host of the Sacrament and covered by a baldachin carried by acolytes, paraded with a vast entourage from the Vatican palace through the nearby streets of the Borgo, as the area was called, and back to the church. On these occasions two great long canopies supported by staves were extended far out, one from the entrance to the Vatican palace flanking the façade on the north, the other from the central portal of the church (Fig 160). The canopies served two intimately related purposes, one practical, the other symbolic. The procession was a grueling exercise, especially for the popes, who were often relatively advanced in age, and the canopies served to shield both the participants and Holy Sacrament from the sun or inclement weather. The canopies also had an equally exigent ceremonial sense, doing honor to the importance of the event and its participants, and especially to the sanctity of the Sacrament itself.
The space before the church thus served a dual function, as an open area to contain the crowds assembled on special occasions, circumscribed by passageways specifically designed for the Eucharistic procession. Considered in this way, the piazza posed the same problem as had the church building itself, namely that of reconciling centrally and longitudinally organized forms and functions. Earlier projects to create a unified and worthy overture to the church had tended to treat the space as a city square, creating an enclosure consisting of covered arcades with offices and apartments on top, recalling portico-lined city streets such as the one projected much earlier for the Borgo by Nicholas V and those common in many northern Italian cities. Bernini's totally different solution may best be understood in relation to the great public act, clearly intended to sound the thematic keynote of his reign, taken by Alexander VII almost immediately after his election on 7 April 1655. On 27 May the new pope introduced a radical innovation in the conduct of the Corpus Domini procession. Instead of walking or riding seated in the traditional sedia gestatoria, in origin a Roman symbol of imperial authority, Alexander was carried on a litter, kneeling and holding the Host before him. The austerity and self-control exhibited in this long, uncomfortable, and intensely concentrated devotion by the agonized (he had a painful infirmity) and perspiring pope, who remained absolutely immobile throughout, is movingly described by eyewitnesses.64 This simple but stunning demonstration of humble adoration inaugurated a new era, defining the entire future development of St Peter's and, with it, the public face of the Catholic Church itself.
Eloquent testimony to this awesome new attitude is in fact that, in planning a suitable frame for the forecourt of St Peter's, Alexander would have nothing to do with the common idea of functionality. He rejected a project that included a usable second story, with the absolute requirement that the porticoes serve no other purpose than as passageways, effectively silencing those who argued that the structures should also have "practical" value. For Alexander, only self-sufficient porticoes could express without adulteration the spiritual values, celebratory and sacramental, he intended them to represent. We shall see that their public utility, which was indeed very great, lay in the work the huge undertaking would provide for the indigent unemployed of Rome, especially after the plague of 1656.
Division of the area into two parts was inherent in the project (Fig 161a, b). The sizes and shapes of these contiguous spaces were also determined by interdependent features of the situation - features that must have seemed providentially "given" and susceptible, in Bernini's imagination, to incorporation into one coherent, unifying thought. The flanking sides of the area immediately in front of the church were fixed by a portion of the Vatican palace to the north, situated diagonally with respect to the façade. This corner of the palace was also a determining factor in the vertical sense, as the pope often made appearances from the balcony of his apartment overlooking the square, for which maximum visibility was required. Matching the palace front symmetrically to the south created the so-called piazza retta (i.e. aligned with the axis of the church), a trapezoid diverging toward the façade, clearly - and inevitably - evocative of Michelangelo's piazza of the Campidoglio. The space thus became the ecclesiastical counterpart to the secular capitol of Rome and the ancient empire.
The lateral, northern extension of the expanded space east of the piazza retta was delimited by the Leonine wall of the city, inviolable because it contained the famous corridor connecting the Vatican with the papal stronghold of the Castel Sant'Angelo. The configuration of this space and its relation to the piazza retta depended from the intersection of two axes, one running longitudinally with respect to the basilica, from the center of the façade of the church to the obelisk that Sixtus V had erected toward the middle of the piazza. The obelisk, in turn, was the point of intersection with an oblique axis, hence the name piazza obliqua, parallel with the church façade. A point on this transverse axis became the center of a circle whose perimeter happened to coincide both with the corner of the Vatican palace and the Leonine wall. When the corresponding circle was drawn on the opposite side of the piazza, the points of intersection between these two circles in turn became the centers for larger circles whose perimeters complete the oval on its long axis. A third axis was a line projected from the north end of the church façade, along the palace façade, through the Borgo Nuovo - the main thoroughfare from the center of Rome - to the front of Castel Sant'Angelo. The intersections of the north lateral circle with this axis determined endpoints of the arc of the colonnade, so as to provide the approach from the Borgo Nuovo with the maximum view of the church façade.
These manifold "coincidences" must have confirmed Bernini's adherence to the quasi-mystical tradition of Pythagorean geometry in which the circle was the most perfect of divinely given forms. These factors, symbolic as well as practical, must also have recommended the oval shape, defined by intersecting circles, rather than the true ellipse, for the piazza obliqua. Although he attributed the conception to the pope himself, Bernini had had much prior experience with this shape, most notably in a chapel he had designed for Urban VIII's Palazzo di Propaganda Fide, the church's office dedicated to the worldwide dissemination of the faith (Fig 162); this was, in fact, the first use of the transverse oval in Rome. The chapel was dedicated to the Three Magi and was therefore replete with astrocosmological symbolism; hence, the plan may also have anticipated the piazza obliqua's reference to the ideal of a universal, all-embracing church, the first witnesses to which were indeed the Magi. At St Peter's the obelisk is flanked by two fountains that give special prominence to the oval's transverse axis, which in turn calls attention to a particular feature of Bernini's design: the columns are aligned in concentric circles behind one another so that the centers of the lateral circles become, literally, vanishing points from which the welter of columns disappears. When seen at an angle, the columns seem multitudinous, disoriented, and dynamic; when seen from the center points, they look simple, regular, and stable. The moving visitor inexorably seeks out these "perfect" vistas, which are in fact marked in the pavement on the axis, perceiving the transitory and yearning for the permanent. Bernini had only recently employed a very different but fundamentally analogous "double perspective" system in the lateral walls of the Cornaro chapel in S. Maria della Vittoria. There the members of the deceased's family are shown in diagonally foreshortened architectural settings (Fig 163a, b), so constructed that when the visitor approaching along the axis of the nave reaches the central vanishing point under the center of the dome, the perspectives "make sense" as a sort of triptych whose lateral wings form one coherent space (Fig 164). In the Cornaro chapel the context was also a gathering of souls, deceased members of the donor's family, united in a kind of disputation of the sacramental event depicted in the central altarpiece, the Ecstasy of St Teresa, and enacted at the altar. Viewed thus, the perspective "resolution" of the space of the piazza at St Peter's stands in a long tradition, especially of sacrament tabernacles and altars, in which the satisfying sense of "truth" mysteriously evinced by perspective had become a metaphor for the mystical coincidence of opposites embodied in the Eucharist itself. 65
One of the most impressive, and unexpected, features of the piazza is the simple sobriety of the colonnades' Doric order, which has surprised observers who expect a more "Baroque," that is, more elaborate treatment, especially from Bernini. The Doric is of course the Greek order par excellence, and one of the most perspicacious students of Bernini, Rudolph Wittkower, made the trenchant observation that "No other Italian structure of the post-Renaissance period shows an equally deep affinity with Greece."66 Part of the motivation for the relatively low and understated design of the colonnades was to magnify by contrast (contrapposto) the height and magnificence of the façade, bereft of the intended bell towers. With respect to the Corinthian order of the façade, the juxtaposition conformed to the traditional increase in elaboration with the superimposition of orders, most famously exemplified in the Colosseum (Fig 165). The juxtaposition made social and ideological sense in that the gravity of the Doric resonated with the piazza's solemn function at Corpus Domini, whose ritual discipline Alexander had greatly augmented at the outset of his reign, and for the common masses of the faithful gathered there to receive the pope's public ministrations. No less important, however, was the resonance Bernini's Doric order created with what was in fact the most important Petrine building in Rome besides the papal basilica, the famous circular and domes tempietto, ringed by antique columns, designed in the early sixteenth century by Bramante to mark the actual spot of Peter's martyrdom (see Fig 264). Bernini had paid specific homage to this martyrial tradition in certain sketches for the Baldacchino, where the upside-down cross of St Peter appears atop the crown, along with the cross of Golgotha. The relationship between the two buildings had already been articulated by Bramante in the cupola of his project for New St Peter's, and the analogy was retained in the basic configuration of the dome as built. As we shall see, Bernini conceived of the semicircular arms of the colonnade as the arms of St Peter embracing the faithful, his head surmounted by the tiara crown as dome.
Bernini's colonnades are extraordinary - more Greek than the Greeks, one might say - in that they eschew an important decorative element, the frieze of triglyphs, of the traditional Doric order. In this form the porticoes clearly coopt the similarly bare first-story order of the Colosseum, the ancient structure whose oval shape the piazza most clearly echoes. The adoption was singularly appropriate as a solemn, even melancholic, reference to the ancient building's service as the "theater" of death for the early Christians who were martyred there - to be resurrected in the cordon of saints whose statues ring the piazza as a triumphal legion of honor guarding the entrance to St Peter's. The association was given a personal reference in a medal designed by Bernini likening the pope's salvific efforts during the plague to the victory of Androcles over the obeisant lion in the amphitheater (Fig 232).
Wittkower's recollection of Greece, however, may have had more substance than he imagined. The allusion suggests an added dimension to the imperious or bucolic "classicisms" Bernini adopted in other contexts at St Peter's. The Doric here becomes a kind of common-or everyman's visual modus orandi whose pristine simplicity and moral rectitude evoke the early Attic style that many ancient rhetoricians sought to retrieve.67 An analogous association was imbued in the design of the colonnades themselves, with the three aisles that provided the sacramental papal procession with a central, covered passageway also protected at the sides. This structure was sanctioned by an elaborate study of the literary evidence concerning ancient colonnades carried out by one of the leading scholars of the day, Lucas Holstein.68 The study concluded that triple porticoes, called chalcidicae from Chalcis in Euboea, were common in the ancient cities of the Greek world, a happy coincidence in view of the fact that Alexander VII, through his namesake, had many associations with the Hellenic tradition. The sources are unclear as to what form the "triple portico" took, but neither they nor the preserved examples suggest that the central passage of the ancient avenues, which were flanked by covered porticoes, was itself covered;69 Bernini's smooth annular vault here is again adapted from the Colosseum (Fig 166). No less important than this invocation of an imagined classical precedent is the occurrence of the same term in the Old Testament, in no less significant a place than the prophet Ezekiel's account of the courtyard of the Temple of God, where he says there was a "porticus iuncta porticui triplici" (Ezek. 42:3).70 In one of the most compendious and popular postmedieval allegorizations of scripture, Hieronymus Lauretus's Silva allegoriarum, first published at Barcelona in 1570 and reissued many times thereafter, the triple portico might designate the mystery of the Trinity: "Porticus atriorum temple, & praecipue porticus triples, mysterium sanctae Trinitatis designare possunt." 71 So far as I can discover, Bernini's quadruple colonnades comprising three covered passages were without precedent in antiquity. The motif constitutes a brilliant architectural neologism that melds classical and biblical references, and so embodies the fundamental concept of Christianity's historical role, proclaimed from the outset by the Fathers of the Church, as the Ecclesia ex circumcisione and ex gentibus, incorporating and superseding its predecessors.
Two species of appropriation and supersession are represented by the architecture of the facedes and cross section of the porticoes (Fig 167). The stepped, pedimented entrances with horizontal entablatures appropriately recall in simplified form the temple front design of the Lateran sacrament altar (Fig 121). Within the colonnades, the raised semi-circular vault with flat wings refers to tone of the most conspicuous of Renaissance architectural motifs, the so-called Serliana (derived from antiquity and popularized by the sixteenth-century architect Sebastiano Serlio). At St Peter's the adaption consisted essentially in the convergence of two important traditional contexts with which the motif was closely associated. One of these was the ancient triumphal fastigium in which the Serliana, covered by a pediment, served as a kind of proscenium or frame for the appearance or passage of the emperor. The most famous fastigium of antiquity had already been baptized, as it were, by the emperor Constantine himself, who erected a huge structure of this kind in the Lateran.72 Conceived as a frame in depth, as it were, the Serliana had an "extended" life in the form of a vaulted, three-aisled passageway. Bernini used the motif in the lateral relifs of the Cornaro chapel and, as a continuation of the piazza porticoes through the entrance to the Vatican itself, in the Scala Regia (Figs 163, 178). In this form the design might be described as at once celebratory and transitional - a triumphal corridor for the procession that also defines the piazza, in which the perspectival resolution from the vanishing points of the two arms of the colonnade comprises the universal embrace of the Corpus Domini.
Another feature that distinguishes the porticoes at St Peter's are the statues of saints that surmount the balustrades. The image they create provides a celestial counterpart to the army of secular heroes who celebrate the Roman imperium on the balustrades of the palaces of the Campidoglio, site of the ancient Temple of Jove and seat of the modern city government.73 Although there was no classical precedent for this arrangement in a portico, colonnades surmounted by statues were shown in a reconstruction of the ancient Capitoline published in 1648, surely an important model for Bernini (Fig 168). Such figures sen atop a colonnade conveyed an additional sense that many have been a factor in the pope's extravagant insistence that the colonnades stand alone with no structure above them. In this way, the statues appear not simply to crown the balustrades but to stand directly on the columns, and so they are described in the contemporary sources. The sculptures were seen not only as a horizontal ring but as an alignment of triumphal columns, the most common form of imperial Roman honorific commemoration. The arrangement created a veritable legion of Christian heroes, joined together by faith, to replace the military heroes celebrated by statues placed on isolated columns in antiquity. A contemporary writer actually described the Corpus Domini procession at St Peter's as the successor to the triumphal processions of the ancient imperators to the temple of the Capitoline Jove. Bernini gave form to this idea.
In a powerful explanation of the project Bernini gave his own definition of the basic theme that animated his conception of the colonnades, which he described as the arms of the mother church embracing all the world, including nonbelievers: "The church of St Peter, being virtually the mother of all the others, had to have a portico that would in fact appear to maternally receive with open arms Catholics to be confirmed in faith, heretics to be reunited with the Church, and unbelievers to be enlightened by the true faith." 74 He even drew a sketch to which this "open-arms" metaphor is transferred to St Peter's represented as pope wearing the tiara (Fig 169). The idea in fact had ancient roots, referring in the first instance to a classical anthropology of architecture - vigorously revived in the humanistic tradition of the Renaissance - in which the harmonious relationships among the parts of the central-plan building were correlated with the ideal proportions of the human body, the so-called Vitruvian Man, whose extended arms and legs touched the perimeter of a circle centered at the navel. In the Christian tradition the metaphor's most familiar application was in the definition of the cruciform basilica as the image of Christ on the cross. Like the architectural forms themselves, the concepts were complementary - one man-focused, the other God-focused - but reconcilable only with difficulty; and both were based on essentially static, symbolic images. Bernini's conception of the relationship between the church of St Peter's and the colonnaded piazza fused these themes, the ecclesiology of the basilica and the universality of the central plan, with a third: the institutional image of the church as Mater Ecclesia. Through this combination he created a new, dynamic metaphor for Christianity's universal embrace. Bernini's sketch of this idea - in itself a startling fusion of concept elevation, ground plan, and bird's-eye view - concerned the preferred placement of a projected but never executed pavilion, appropriately called the Terzo Braccio, the third arm, at the entrance to the piazza. The purpose of the structure was at once conceptual and visual: it provided the optimum viewpoint from which to grasp the shape and space of the entire square, and hence its universal meaning. The difference from the preceding traditions is that Bernini's metaphor involves not only the static ground plan but the elevation as well, and conceives of the church and the piazza together as a unified whole, not a passive receptacle but a living organism acting on behalf of mankind.
A further unexpected but sharply illuminating insight into the kind of thinking that underlay the project is provided by the four explicative inscriptions, composed by the pope himself. They were placed at the outer and inner extremities of the arms of the colonnades, the latter pair at the junctures between the colonnades and the corners of the piazza retta. Except for the one at the southeast entrance, which records the completion of the work in 1661, the texts combine passages from scripture in such a way as to define the nature and meaning of the structure, and address the viewer, exhorting him, in effect, to follow the pope's example. The texts are all from the Old Testament, as if to demonstrate the fulfillment of their auguries in the New. The inscription at the northeast entrance states the practical function of the colonnades, but in terms that express their higher import through the prophet Isaiah's description of the tabernacle/umbrella in the Kingdom of God: IN UMBRACULUM DIEI AS AESTU IN SECURITATEM A TURBINE ET A PLUVIA (Isa. 4:6: "et tabernaculum erit in umbraculum diei ab aestu et in securitatem et absconsionem a turbine et a pluvia." [And there shall be a tabernacle for a shade in the daytime from the heat, and for a security and for a covert from the whirlwind, and from rain; Douay-Rheims]). At the southeast entrance is the dedication: ALEXANDER VII PONTIFEX MAXIMUS A FUNDAMENTIS EXTRUS[IT] ANNO SALVAT[ION]IS MDCLXI. The inscriptions at the corners conflate Old Testament phrases in praise of God into prescriptions that evoke the Corpus Domini procession and the Eucharist worship it celebrated. That on the northwest invokes the procession and worship in the church: VENITE ASCENDAMUS IN MONTEM DOMINI ADOREMUS IN TEMPLO SANCTO EIUS (Come, let us ascend the mount of God, let us worship in his holy temple). The text combines Isaiah 2:3, "et ibunt populi multi et dicent venite et ascendamus ad montem Domini" (And many people shall go, and say, Come, and let us go up to the mountain of the LORD), with Psalm 137:2, "adorabo ad templum sanctum tuum et confitebor nomini tuo super misericordia tua et veritate tua quoniam magnificasti super omne nomen sanctum tuum: (I will worship toward thy holy temple, and I will give glory to thy name. For thy mercy, and for thy truth: for thou hast magnified thy holy name above all). The mountain alludes to the Temple on the Mount in Jerusalem, to the Mons Vaticanus where St Peter's and the Vatican are located, and to the mountains that form part of the arms of the Chigi family. At the southwest: VENITE PROCIDAMUS ANTE DEUM / IN TEMPLO SANCTO EIUS ET NOMEN DOMINI INVOCEMUS (Come, let us bow down before God in his holy temple, and let us invoke his name), combining Psalm 94:6, "venite adoremus et procidamus et ploremus ante Dominum qui fecit nos" (Come let us adore and fall down: and weep before the Lord that makes us) with Psalm 114:4, et nomen Domini invocavi o Domine libera animam meam" (and I called upon the name of the Lord. O Lord, deliver my soul).
The genesis and meaning of the entire project were subsequently distilled into a medal issued in 1664 in commemoration of that extraordinary innovation, to celebrate the decennalia, or decadal anniversary of the pope's election (Fig 170). 75 The image chosen for the occasion, Alexander kneeling in the Corpus Domini procession, is a measure of the importance attached to the event and the pope's extraordinary innovation. The motto, "Prodicamus et adoremus in spiritu et veritate" (Let us kneel and adore in spirit and in truth), is again an ingenious amalgam of two scriptural passages, one from the Old Testament, the other from the New, which encapsulate the essence of the Corpus Domini devotion. The first part comprises David's exhortation to praise God in Psalm 94:6, the same text used in the southwest colonnade inscription. The second part repeats John's prescription for the inward disposition required of those who worship God, "God is a Spirit; and they who adore him, must adore him in spirit and in truth" ("Spiritus est Deus, et eos, qui adorant eum, in spiritu et veritate oportet adorare"; John 4:24). Together the passages describe the inward and outward expression of devotion proper to the Eucharist. The kneeling, immobile attitude of prayer had long been the canonical mode of devotion to the Eucharist - perpetual adoration was, as we shall see, the highest calling of the angels in heaven - but introducing it into the Corpus Domini celebration served to transform both traditions: the Eucharistic devotion was given a dynamic movement and an all-embracing scope, and the traditional procession exultant triumph was enshrined, as it were, in a powerful sign of humble public worship, specifically associated with the Eucharist. The medal and its inscription have another sense as well. The Catholic understanding of the Eucharist, or rather the nature of the Eucharistic sacrifice in the mass, was one of the major targets of the Protestant reformers and had been emphatically reaffirmed at the Council of Trent. The council specifically imposed the Corpus Domini procession as public demonstration of belief in the truth of the Eucharist, which would overcome and, it was hoped, convert the enemies of the church.76 Alexander's innovative inaugural procession and Bernini's welcoming piazza and colonnades gave new form to the new spirit that inspired the quintessential tenet of the church and its claim to universality.