This cultivation of purely aesthetic values and interests, allied to a proliferation of new kinds of secular art in northern Europe and Italy, cannot obscure the fact that fifteenth-century art remained predominantly religious. To the orthodox definition of the threefold purpose of religious images — as instructions for the illiterate, as aids to memorising scripture and sacred history and as stimuli to meditation — the urban mysticism of the fifteenth century, ultimately Franciscan and Dominican in inspiration, added its own emphasis on visualisation. Seeing, so closely associated with believing, had its own sacramental value. The institution of the feast of Corpus Christi placed an emphasis on lay visual participation with the consecrated host that led directly to new types of eucharistic display, such as the elaborate metalwork monstrance, and the spectacular sacrament house, which appeared in Germany and the Netherlands in the form of a monumental Gothic pinnacle (St Lorenz, Nuremberg, 1493—6) (plate 1). The sermon and the illustrated devotional handbook, the mainsprings of fifteenth-century piety, instructed meditation as visualisation, and left their traces in religious imagery. The varied emotions experienced by the Virgin at the Annunciation were laid out by the preachers as successive spiritual and mental conditions, simultaneously re-experienced in the pious imagination, and registered in the repertory of gesture and feeling found in numerous Quattrocento Annunciations, particularly those of Fra Angelico (c. 1387—1455), the only Italian artist of the century to be singled out by both Vasari and Landino for his devoto. The Italian Garden of Prayer recommends its readers to set the events of the Passion in their own city, and enact them imaginatively with actors of their own acquaintance — an injunction rarely followed in Italian painting, which provided only a generalised framework within which the viewer could supply his own detail and action, but much more literally obeyed in the north, where Netherlandish artists (notably Robert Campin and his workshop) introduced a new type of Virgin and Child image, placed in an upper-middle-class domestic interior, and where Konrad Witz set his Miraculous Draught of Fishes (Geneva, 1444) on his own lake of Geneva (plate 16).
The private and sentimental character of this piety corresponds to the proliferation of small devotional works of art for private use in home or chapel, usually depicting the Virgin or the sufferings of Christ: mass-produced cruci fixes, the Man of Sorrows, diptychs of the suffering Virgin and Christ crowned with thorns, St Veronica’s sudarium, small panel paintings with prayers on their shutters (the counterparts to the fashionable illuminated Book of Hours), and in Florence Madonna images mass-produced by specialist madonnieri (as Vasari snootily called them), the most charming and humane in cheap white-glazed terracotta by the della Robbia family. At the opposite end of this devotional continuum stood the altar retable, the supreme focus of religious emotion and communal identity. The van Eycks’ Ghent altarpiece (whose monumentality belies the notion that Flemish art is miniature) effectively translated the format, the scale and the theological universality of the Gothic cathedral portal into the interior of the church, and enlivened its narratives by a new, persuasive naturalism. But it was in southern Germany, in the last quarter of the century, at a time when Germany gained its international reputation for what Agrippa of Nettesheim called ‘its piety and its craftsmen’, that the altar retable acquired its most expansive form. Composed of a large central corpus with sculpted figures, flanked by painted or sculpted wings, and crowned by a high superstructure of Gothic tracery — the whole carved in easily worked limewood (though often gilded and painted with an hallucinatory brilliance) — the German altar-piece brought together all the technical and aesthetic possibilities of micro-architecture, sculpture and painting in a majestic Gesamtkunstwerk unprecedented in Europe since the High Gothic cathedral. Almost all were commissioned by a small, wealthy urban patriciate, or by clerics from the same patrician background. The largest of them, like Veit Stoss’s giant for St Mary’s in Cracow (1477—89) (plate 17), were high altars that proclaimed the identity of the whole community; smaller commissions decorated the chantry chapels of religious confraternities. Their arrays of saints, presented in the intimate and familiar style of a sacra conversazione, and each invoked as a specialist protector and prophylactic, voiced the intense need of individual laymen and their confraternities for spiritual insurance. The popular success of these giant prayer machines laid them open to charges of ostentation and idolatry. For radical reformers like Zwingli, Sebastian Franke or Savonarola, fifteenth-century religion had become so implicated in imagery that reform also entailed destruction.