In connection with the direct practice of Donatello, it is worth while referring to some words of Francesco Bocchi, a rhetorical eulogist of the arts and artists of his native Florence, who wrote in 1571 a literary effusion on the sculptor’s St. George. He notes in his introduction that Donatello was accustomed to compose his marble figures compactly and to avoid projecting hands and arms, while for his effigies in bronze he used much greater freedom in action. The difference is really one of material, and Donatello’s practice of working directly on the marble would necessarily involve this restraint in composition. Anyone accustomed to deal with marble blocks as vehicles of artistic expression, would avoid unnecessary projections as these cause great waste of material and expenditure of time. When plastering clay or wax on a flexible armature this consideration is not present, and modelled figures will naturally be freer in action than carved ones. As will presently be seen, certain marked differences in the treatment of relief sculpture depend on these same considerations of material and technique.
In direct work on the marble there is of course always the danger of the sort of miscalculation that Vasari goes on to notice. Greek figures sometimes show variations from correct proportions, for example, the left thigh of the Venus of Milo is too short, but the errors are not such as to destroy the effect of the works. Greek work in marble shows a marvellously intimate knowledge on the part of the carver of his material as well as a clear conception of what he was aiming at. Even Michelangelo yields in this respect to the ancients, for though no one was ever more thoroughly a master of the carver’s technique, he made serious mistakes in calculating proportions, as in the ‘Slave’ of the Louvre, where he has not left enough marble for the leg of the figure. Moderns generally have not the ease which tradition and practice gave to the Greek sculptors, and the full-sized model is now a necessary precaution.
ITALIAN AND GREEK RELIEFS.
[§ 52, Pictorial or Perspective Reliefs, ante, p. [154].]
Vasari ascribes comprehensively to the ‘ancients’ the invention of the pictorial or perspectively treated relief, which was not in use in mediaeval times, but came into vogue in the early years of the fifteenth century. The first conspicuous instance of its employment was in the models by Ghiberti for the second set of gates for the Baptistry at Florence begun in 1425, but as these gates were not finally completed till 1452, other artists had in the meantime produced works in the same style. Donatello’s bronze relief of the beheading of John the Baptist, on the font at Sienna, was completed in 1427 and shows the same treatment in a modified form. It is a treatment often called pictorial as it aims at effects of distance, with receding planes and objects made smaller according to their supposed distance from the foreground. The style has been sufficiently criticized, and it is generally agreed that it represents a defiance of the barriers fixed by the nature of things between painting and sculpture. It depended mainly however not on the influence of painting but on the study of perspective, which Brunelleschi brought into vogue somewhere about the year 1420. Brunelleschi’s perspectives, or those which he inspired, were worked out in inlaid woods, or tarsia work, see postea, p. 303 f., and exhibited elaborate architectural compositions crowded with receding lines. These compositions were adopted by Donatello and others for the backgrounds of their figure reliefs, and Ghiberti filled his nearer planes with a crowd of figures represented as Vasari describes according to the laws of linear, and so far as the material permitted, of aerial perspective.
The question of the amount of warrant for this in antique practice as a whole calls attention to an interesting moment in the general history of relief sculpture. This has been dealt with recently by Franz Wickhoff, in the Essay contributed by him to the publication of the Vienna ‘Genesis,’ and issued in an English translation by Mrs Strong under the title Roman Art (London, 1900), and also in Mrs Strong’s own Roman Sculpture (London, Duckworth, 1907). The tendency to multiply planes in relief, and to introduce the perspective effects and the backgrounds of a picture, shows itself in some of the late Greek or ‘Hellenistic’ reliefs, published by Schreiber under the title Die Hellenistischen Reliefbilder (Wien, 1889 etc.), and more especially in the smaller frieze from the altar base at Pergamon. Etruscan relief sculpture is also affected by it. It is however in Roman work of the early imperial period that we actually find the antique prototypes for the kind of work that Vasari has in his mind. The reliefs on the tomb of the Julii at St Rémy, of the age of Augustus, those on the Arch of Titus, and most conspicuously the decorative sculpture connected with the name of Trajan, are instances in point. They show differences in plane, and occasionally a distinct effort after perspective effects, and it is possible that the study of some of these Roman examples by Brunelleschi and Donatello at the opening of the fifteenth century may have contributed to the formation of the picturesque tradition in Florentine relief sculpture of the period. This style was however by no means universal in Roman work. The carved sarcophagi are not much influenced by it, and these sarcophagi are of special importance in the later history of sculpture, in that they were the models used by Nicola Pisano and the other French and Italian sculptors of the so-called ‘proto-Renaissance’ of the twelfth and thirteenth centuries. In relation to antique sculpture as a whole the pictorial style is quite abnormal. The genius of the classical Greek relief is indeed totally opposed to that of the Italian reliefs represented centrally by those of Ghiberti. The difference is fundamentally one of material and technique. It is the same distinction that was drawn by Michelangelo in his letter to Benedetto Varchi, and noticed already in the Note on ‘The Nature of Sculpture,’ ante, p. [179], the distinction, that is, between sculpture that proceeds by additions, ‘per via di porre,’ and that which advances by taking material away, ‘per forza di levare.’ The normal Italian relief was in cast bronze and was necessarily modelled work. The classical relief was in marble and was essentially carved work, for the diversifying of a flat surface. When the Greek relief was in baked clay it was generally stamped from moulds and not modelled up by hand. The cast bronze relief in classical Greece may be said only to have existed in the form of small plaques for the decoration of vases or other objects in metal. The normal bronze relief in the ancient world was beaten up in sheet metal by the repoussé process.
In the case alike of the relief carved on the marble slab, or stamped in clay from moulds, or beaten up in the sheet of metal, the nature of the technique renders flatness of effect almost obligatory. The Greek decorative relief cut ‘per forza di levare’ in a smooth marble slab, that is most often one of the constructive stones of an edifice, naturally sacrifices as little of the material as is possible, and in all Greek reliefs, whether low or high, as much as possible of the work is kept to the foremost plane, the original surface of the stone. Again, a mould that is undercut, or at all deeply recessed, cannot be used for stamping clay, while the difficulty of relief work in sheet metal is greatly increased in proportion to the amount of salience of the forms. Hence the general flatness of the antique relief, observable even on the late Roman sarcophagi which served as models at the first revival of Italian sculpture. Whether the field of the relief is open or crowded, the objects all come together to the front.
How different are the conditions when the relief is modelled up by hand in clay or wax! Here the starting point is the background, not as in the carved relief the foreground, and the forms, worked ‘per via di porre,’ can be made to stand out against this with an ease and effectiveness which tempt the modeller to try all sorts of varieties of relief in the same composition or the same figure, and to multiply planes of distance till the objects on the foremost plane are starting out clear of the ground. There is direct evidence (see ante, p. [194]) that in the first century B.C. the use of clay modelling as a preliminary process in sculpture was greatly extended, and Roman pictorial reliefs may themselves have been influenced from this side. There is no question at any rate that the Italians of the Renaissance surrendered themselves without hesitation to the fascination of this kind of work, and the style of it dominates their later reliefs. The contrast in this respect between Ghiberti’s second, or Old Testament, Gates, and his earlier ones which adhered to the simpler style of Andrea Pisano’s reliefs on the first of the three Baptistry Gates, is most instructive. Andrea’s reliefs are in character mediaeval, and the nearest parallel to them are the storied quatrefoils on the basement of the western portals at Amiens. It is worthy of notice how classical these are in style, and this is due to the fact that like Greek reliefs, such as the frieze of the Parthenon, they were cut in the constructive stones of the edifice in situ, and are in true stone technique.
This contrast of Greek and Italian reliefs furnishes a most conspicuous object lesson on the importance of material and technique in conditioning artistic practice. As was pointed out in the Introductory Essay, these considerations have not in the past been sufficiently emphasized in the scheme of education in design recognized in our Schools of Art, though in several quarters now there is a promise of better things.