Eric Will
United Kingdom

“Ah, but a man’s reach should exceed his grasp,
Or what’s a(n artist’s) Heaven for? . . .”
— After Robert Browning’s “Andrea del Sarto,” 1855 ^1,2 (author’s italics)

The bedside is a comfortable thinking space for clinicians. On occasion, just there, they bring to mind the clinical patterns that point to a differential diagnosis. Should a recognized pattern suit the clinical case, a search begins for anything that really does not fit. Karl Popper’s “trial by falsification” is in widespread, routine employment.³ Plausible and tested inference, then, plays a part in clinical diagnosis, just as it does in one source of the metaphor of patterns, the potential to expand visual experience. The artist’s illusions of space and form depend on inference and the “eye” is not easily deceived. Unless the pictorial regressions and coordinates of perspective achieve a threshold of credibility in the viewer, falsification is immediate. As it happens, the observation of a particular bedside offers an illustrative example, the orientation of a Sienese bedcover in a fourteenth century Italian painting.

The uniformly convincing presentation of three-dimensional (3D) space on a two-dimensional (2D) surface awaited the articulation of linear perspective and single vanishing point by the Florentine polymaths Brunelleschi and Alberti in the early fifteenth century.^4,5 It had been preceded by a variety of attempts at perspective.⁶

Thirteenth century Italian painting was concerned largely with Christian imagery. It grew out of a tradition of icons, where religious observance was prompted by images based on a limited range of symbolic, idealized elements. As Western Christianity developed there was a progressive concern for bringing the ineffable towards reality and the viewer from prayerful contemplation to notional participation. Fourteenth century artists gradually eschewed the svelte Byzantine figures, while exploring visual tricks to create the impression of depth in their scenarios.

Ceiling space was used commonly as the indicator of an area of floor. Vertical columns were used to map out the ground despite uncomfortably splitting the scenes. Occasionally they delineated meaningful spaces, creating atmospheric contrast in the binary exchange of the Annunciation, for example. In the event, the use of pillars was only partially successful. The visual inference of floor area from overhead is only ever insecure, even when the footing is evident. Who can tell reliably where the shadow of a patrolling bird of prey might fall?

Other architectural devices included oblique rotation, multifaceted thrones, plinths, and steps. Sometimes a pergola was used to imply group interaction, often in relation to a cill or sidewall. The use of overlapping figures and structures was natural but, when prominent, obstructed the action. An open “doll’s house” allowed a composite storyboard.⁷ These constructions were often combined but, in the absence of any unifying principle, feel contrived. Despite efforts to model figures and drapery some representations remained unconvincing, for example a figure meant to be reclining on or in a bed or couch.

The Lorenzetti brothers, Ambrogio and Pietro, of early fourteenth century Siena (both d.1348), made the most effective efforts toward 3D visual deception prior to Alberti’s transformative account. They used patterns as coordinates to place figures securely in a receding scenario.^8,9 A triptych of 1342 attributed to Pietro is the main exhibit here (fig 1).^10-13 The topic was obstetrical, entirely filling two of the panels. In a traditional tableau of “the Birth of the Virgin” Pietro shows the postpartum incumbent (a dominant St. Anne) lying on a bed that is covered by a patterned blanket. The pattern is of connected squares that convey a consistent linearity across the bed in both directions. This plaid is effectively a checkerboard of coordinates that locate the body of the mother better than simply dropping her outline onto the bed.

By contrast, Giotto (1315) displayed just a transverse weave on the bed of his St. Anne, which gave no clue to her position. In other contemporary versions of the Birth of the Virgin, and the Birth of St John the Baptist, a plain bedspread failed to secure a comfortable recumbent image.¹⁴

In this lying-in, Pietro carefully adds glimpses of a patterned floor, which contributes a second virtual grid. That defines the local positioning of the asymmetrical bedside attendants. Both grids offer diagonals that contribute to overall perspective. Their regression lines, and others within the picture, converge on a central area of the piece, rather than a single (Albertian) vanishing point.¹⁵ However, the combination of patterned bed and floor gives a convincing depth to the ‘room’. The sheer dominance of the plaid in this collaboration becomes apparent when the grids are erased in turn from digitized images. The position, area, and color of the blanket are what really create the effect. Pietro had tried a similar plaid/floortile combination in earlier work, but without the collaborative orientation and near convergence of both sets of diagonals.

He also adopts another traditional device, a regressing side corridor containing the expectant father and revealing distant facades. This tempts the viewer’s gaze into the pictorial space, rather as the rivers and roads of later artists link the fore- and back-ground to provoke an anticipation of progressive depth. As observed here, the outer panels recede and the center proceeds. For once, over all three sections, the starry ceiling canopy is placed convincingly.

With these multiple reinforcements of the 3D illusion, Pietro’s reach towards successful perspective well exceeds his grasp.

The topic of lying-in was frequently pictured as part of the Christian story, but also in the secular tradition of the desco da parto, a commemorative birthing tray.¹⁶ Such bedroom scenes provide a cornucopia of material in the study of medieval and Renaissance interior design.¹⁷ Sienese representations of the time often include a quadrate bedcovering in scenes other than lying-in. There seems no general concern to emphasize the richness of the material, the basic plaid likely to have been an everyday item.¹⁸ The coincidental exploitation of Pietro’s boost to perspective is exceptional.^{19, 20}

Commentators have been impressed that with Birth of the Virgin Pietro was midwife to something “before its time” in the coherent portrayal of space. It is apparent that the Lorenzetti brothers, like some of their contemporaries, were aware of the power of convergent regression lines and patterned coordinates to create perspective effects. How much they reflected on them as general phenomena is uncertain. The underdrawing here is said to show deliberation, but an element of serendipity cannot be discounted.²¹ The intellectual history of medieval painting is incomplete, despite the vocational expertise and impressive use of counter-transference by scholars and connoisseurs.²² The brothers’ intuitions are barely evident in works across the remainder of the fourteenth century, for reasons disputed by academics.²³ After Alberti’s account of 1435 the enhancement of perspective through traditional motifs was anyway made unnecessary by grander compositional devices.

Alberti enjoined that no pictured objects could appear real unless they stood in a determined relationship to each other.²⁴ The foreshortened checkered pattern of uniform squares that could specify relative positions in a foreground were much valued by contemporaries.²⁵ Unsurprisingly, this was connected to the demands of the subject being represented. When verisimilitude was dependent on the precise location of center ground figures, even fourteenth century artists had taken up localization on patterned floors (figs 2,3). Indeed, in scenes of the flagellation of Christ they became a traditional feature.

Nevertheless, the axes of perspective, and coordinate-defined foregrounds were not quickly appreciated by medieval artists. Perhaps their steep-sided, higgledy-piggledy, hilltop towns deprived them of vanishing points? (fig 4)²⁶ Even experience indoors, where the timber beams of medieval ceilings appear to converge when viewed from a bed or chair, prompted little appearance in their designs. In practice, less than rigorous diagonal intercepts were “good enough,” even if they only encouraged rather than impelled a viewer’s attention to the focus of a composition.

As for the foreground, checkered surfaces have long been familiar to Homo ludens.²⁷ Chess relies on the co-ordinates of a map-like board for the placement of pieces and the conventions of their movement. The localizing pale and dark squares of the modern 8×8 chessboard became conventional after 1100, two centuries before the Sienese brothers were active. In some sense they too were players in a game, the explicit rules of which had yet to be fully recognized.

The orientation of a Sienese bed-blanket furnished convincing depth to a conventional religious narrative and bolstered an impression of recumbency in the central character. For the Lorenzettis, the co-incidental patterns of bed and floor drew their reach in perspective to exceed their pre-principled grasp. A century later the grasp of linear perspective shown by Alberti depended on a chequered ground for which the Sienese blanket had been surrogate.

Experienced modern clinicians, through non-visual inference, also take advantage of patterns to extend their provisional diagnosis of atypical presenting complaints. Indeed, it seems fair to say, from a certain perspective, that the notional diagnostic gap of “reach-minus-grasp” becomes an intellectual space at the bedside; an inferential vacuum that provokes subsequent, more objective, clinical investigations.

Of course, the modern clinical status quo has antecedents. Just as the Italian fourteenth century is considered a “proto-Renaissance” leading into the humanism of the fifteenth century, so the idealized, rather abstract, medicine of the twentieth century can be seen giving way to a preoccupation with patient-centricity in the twenty-first. Even more compelling is to view current patterns of diagnosis as “proto-Artificial Intelligence”(AI). Computerized decision support in the form of machine-learning is being primed to identify diagnostic patterns that the individual clinical intelligence cannot see or retain. In other words, and without hyperbole, AI is the means by which clinical reach may yet come truly to exceed its grasp, and that not incidentally but by design.

End notes

1. James Reeves, Selected poems of Robert Browning (London: Heinemann, 1977), 97-105.
2. Hilary Fraser, The Victorians and Renaissance Italy (Oxford: Blackwell 1992), 170-78.
3. Karl Popper, The logic of scientific discovery (London: Routledge, 2002). Of course, clinical expertise entails many additional features.
4. Leon Battista Alberti, On Painting (London: Penguin Books, 2004).
5. Martin Kemp, The Science of Art (New Haven: Yale University Press, 1990), 9-11.
6. Samuel Y. Edgerton, The Mirror, the Window, and the Telescope (New York: Cornell University Press, 2009), 58-64.
7. Miriam Schild Bunim, Space in medieval painting & the forerunners of perspective (New York: AMS Press, 1970), 148-50.
8. John White, The birth and rebirth of pictorial space. 3rd edition (London: Faber and Faber, 1987), 99-101.
9. J V Field, The Invention of Infinity. Mathematics and Art in the Renaissance (Oxford: OUP, 1997), 37-40.
10. Timothy Hyman, Sienese Painting (London: Thames & Hudson, 2003).
11. Diana Norman, Painting in Late Medieval and Renaissance Siena 1260-1555 (New haven: Yale University Press, 2003), 114-8.
12. Hans Belting, Florence and Baghdad (Cambridge, Mass: Harvard University Press, 2011), 142-45.
13. Ed Diana Norman, Siena, Florence and Padua, Art , Society and Religion 1280-1400, Volume II: Case Studies (New Haven: Yale University Press, 1995), 203-5 (plate 250).
14. Peter Thornton, The Italian Renaissance Interior 1400-1600 (London: Weidenfeld and Nicholson, 1991). There are more than forty representations of lying-in included in this account. Only later Italian and N. European works using folds in a plain bed covering gave a compelling representation of ‘being in bed’. Del Sarto’s own version of 1513 is a case in point (p150, plate 165).
15. Bunim, Space in medieval painting.
16. Thornton, The Italian Renaissance Interior 1400-1600, 252.
17. ibid.
18. ibid, 162-65.
19. Bernard Berenson, Homeless Paintings of the Renaissance (London: Thames and Hudson, 1969), 39.
    Follower of Niccolo Buonaccorso, 1370-88 Annunciation (Wadsworth Atheneum, Hartford, Connecticut (figure 47). Even so, the action and vanishing points are dislocated.
20. Ed Diana Norman, Siena, Florence and Padua, Art, Society and Religion 1280-1400, Volume II: Case Studies (New Haven: Yale University Press, 1995), 270.
    Paolo di Giovanni Fei, Birth of the Virgin with Saints, 1391, contains all of the traditional motifs, including the Sienese blanket, without unity of composition (plate 254).
21. Kemp, The Science of Art, 11.
22. Berenson, Homeless Paintings of the Renaissance.
23. Diana Norman, ‘Art and religion after the Black Death’, in Siena, Florence and Padua: Art, Society and Religion 1280-1400, Volume I: Interpretative Essays. Ed Diana Norman (New Haven: Yale University Press, 1995), 177-95.
24. Alberti, On Painting, 56.
25. Michael Baxandall, Painting and Experience in Fifteenth-century Italy. 2nd Edition (Oxford: OUP 1989), 124-28. Browning wrote also of Fr Filippo Lippi, whose version of the subject has a strongly chequered floor but a plain bedcover (p132, plate l71).
26. Timothy Hyman, Sienese Painting (London: Thames & Hudson, 2003), 177. The representation of urban gradients is stark in plate 151.
27. Roger Caillois, Man, Play and Games (London: Thames & Hudson, 1962).