Masaccio's "Holy Trinity," in the Florentine church of Santa Maria Novella, is one of the most intellectually complex and deeply moving pictures ever painted, remarkable not only for its precocious naturalism, which initiated the Renaissance painting style, but also for the way its depiction of the material world is infused with deep metaphysical significance. It is both the most rational and the most mysterious of images.
The painting owes its verisimilitude to a number of groundbreaking innovations. Its life-size figures are rendered with a new kind of sculptural modeling, which makes them seem to occupy real space. And its architectural setting, based on elements from classical antiquity, is constructed with "scientific" one-point perspective. This creates a convincing sense of depth and places the viewer in a fairly specific physical relationship to what is depicted. Masaccio creates the illusion that a whole new space has been opened up before us, as if a new chapel had been cut into the wall. At the time it was painted, the realism of this picture was so startling that viewers could well have believed the Holy Trinity was actually right there in the church.
Masaccio's painting is unusual in combining the Trinity with a Crucifixion scene: The Virgin Mary and St. John stand under the cross, which is set on a mound of dirt that symbolizes Golgotha. Mary, in particular, lends a moving human element to this austere image. She is rendered as if clearly seen from below and in three-quarter view, which gives her greater physical presence than the other figures, who are depicted in profile or full-face and seen as if at eye level. The resigned, matter-of-fact gesture by which she invites us to contemplate her Son on the cross is not only profoundly moving but also emphasizes her role as an intercessor.
Below the patrons who kneel just outside the sacred space is a skeleton laid out on a sarcophagus. Above it, an inscription reads: "I once was what you are now, and what I am you also will be." This memento mori, placed under a symbol of Golgotha, suggests that the skeleton represents both Everyman and Adam, widely believed to have been buried under the place where Christ was later crucified. The reminder of physical death is contrasted with God the Father holding the cross, offering the promise of everlasting life.
The perspective construction plays a central role in creating levels of meaning. The vanishing point, and thereby the viewer's eye-level, is just below the foot of the cross; this places us in a position of submission, below the donors but above the skeleton. The deep space described by the coffered vault relates the sanctity of the figures to how far away from us they seem to be. In earlier painting, the hierarchy of sanctity was expressed by the relative height of the figures within the composition. Here, for the first time, sanctity is also directly coordinated with depth: the patrons are lowest and closest, while God the Father is highest and farthest away.
The picture's unprecedented realism posed philosophical problems for the painter. In medieval representations of the Trinity, God the Father was represented as much larger than Christ, who was in turn taller than any other figures; and all were usually set against a flat, gold-leaf ground. In such images, the Divine figures exist outside space and time. Masaccio, by rendering his figures with such realism in a tangible architectural space, subjects them to the laws of nature. This is clear in the way God the Father stands so firmly on the ledge beneath him, His feet depicted in foreshortened perspective, rather than floating free as in earlier works.
Such a rendering ran the risk of having the physical realism of the image overwhelm its spiritual presence. To prevent this, Masaccio built a number of adjustments and subtle contradictions into his apparently rational perspectival composition. For example, since the figures are roughly life-size, the artist had to deal with the problem of maintaining the hierarchy between them without sacrificing the illusion of real space. When figures are rendered in perspective, those farthest away seem to be the smallest; but following that principle too literally here would run counter to the sanctity of the subject. Masaccio found a brilliantly simple solution: Because they kneel, the two donors, who by the laws of perspective should be the largest, look shorter than the holy figures behind them.
Within the hallowed sanctum, the adjustments of space are more subtle. The perspective is constructed inconsistently, which some have seen as evidence of Masaccio's imperfect understanding of it. But these inconsistencies are in fact central to the compressed levels of meaning the picture conveys. For example, Masaccio seems to have combined optical perspective with a surface geometry based on the calibrations of an astrolabe, used by astronomers and understood at the time to be a symbol of a divinely ordered universe. By overlapping two mathematical systems, he merged the depiction of time-bound surface appearances with an awareness of eternal underlying causes.
The perspective in this painting is sufficiently accurate to be convincing, but purposely inexact enough to make space for the supernatural. This is strikingly evident in the representation of God the Father, who stands on the narrow ledge attached to the back wall of the barrel-vaulted space, which would appear to be about nine feet deep. Yet at the same time, He is also present at the front of this same vaulted space, supporting the body of his Son on the cross. This discrepancy in perspective allows God to be in more than one place at a time—a supernatural phenomenon made all the more remarkable by the painting's apparent realism.
Among other things, this great fresco, painted on the wall of a Dominican church, is a stunning affirmation of the great Dominican theologian St. Thomas Aquinas's assertion that to be "everywhere primarily and absolutely is proper to God." What better place could there be to state this with such subtlety than in a representation of the Holy Trinity, whose paradoxical consubstantiality—distinct, yet of one being—is a central mystery of Christian faith.
To have been able to convey such a dynamic amalgam of reason, compassion, mysticism and grace in the static medium of paint on plaster is surely the greatest of Masaccio's achievements.
—Mr. Flam is an art historian and former art critic for the Journal.