For central Italians, the guiding principle expressed through disegno in painting was the mental process of invenzione. Invenzione became the force which allowed the artist to go, in his creative process, beyond the simple imitation of nature–“A non solo d’imitar, ma di superar la natura”. Titian’s position within Venetian cinquecento art theory in connection with Michelangelo was expressed in Lodovico Dolce’s Aretino (1557). Dolce praised above all Titian’s invenzione that is, the workings of the artist’s genius in his manipulation of the chosen thematic material. This seems to have been a concerted effort on Titian’s part in regard to all of the arts. Panofsky in fact connected Titian’s poesie and sixteenth-century art theory through a reconsideration of painting as an intellectual discipline, especially in relation to poetry. Titian’s frequent departures from Ovid’s literary models shows his intellectual affinity with the poet’s aims, while asserting his creative autonomy (invenzione) and equality with, even supremacy over, the poet. In the visual arts, Titian asserted his artistic supremacy over the great masters of central Italian Renaissance art: Michelangelo and Raphael. By a unity of invenzione with colorito, Titian reached a perfect combination of both the rational and sensuous qualities of art beyond the imitation of nature. To quote Aretino’s boastful praise, Titian usurped nature’s life-giving powers to such a degree that he was “hated by a jealous Nature as a competitor.” To be sure, Titian’s impresa of c. 1562, “NATURA POTENTIOR ARS” (“Art more powerful that Nature”) was a counterattack against central Italian claims that colorito was a mere imitation of nature. It was also a response to Michelangelo’s statement that Titian unfortunately lacked training in disegno. This criticism of Titian by his archrival Michelangelo implied that the Venetian, proficient a colorist as he was, could profit from learning the skill of drawing.
Therefore, it is invenzione as a manipulation of thematic material and as extension of the disegno versus colorito debate that we have to look to as a guiding principle to the thematic details of Titian’s Pieta.
Even more astute is Titian’s integration of the separate thematic compositional parts into a more dynamically unified ensemble. Titian responded to Vittoria’s semi-circular arrangement of isolated, incommunicative figures with his own grouping of figures around the central characters in front of an illusionistic niche. In the Pieta the Virgin’s face and that of Christ, along with his body, are fully illuminated. As a result, Christ is the most resplendent figure in the work, and thus its focus. Because of this light and Christ’s pale complexion, his body seems to glow from within. Together with his halo, this aura-like light seems to anticipate his Glory, alluding to his role as Salvator Mundi. The painted niche visually isolates the central group, establishing the equivalence of the Virgin to the altar upon which the Host, Christ, rests. The frame around the niche, which emphasizes the central group of the Virgin and Christ, focuses the viewer’s attention on them and, in a sense, functions rather like the illusionistic sculpted frame of an altarpiece.
This use of the niche as frame parallels with Vittoria’s grouping of his figures around and in front of the sculptural frame of the Zane Altar. In the painting, this results in a breakdown of the strict separation of the painting’s internal space and the actual space of the church, an element accentuated by the actions of the other participants. The Pieta group is flanked by Mary Magdalene to the left. She is shown gesturing in an agitated manner, with her face turned toward her right, originally in the direction of the nave. Here she is in her role of primary mourner in the Lamentation, identifiable by her expansive, pathetic gestures. Counterbalancing the Magdalene to the right is St. Jerome, who has been recognized as a self-portrait of Titian. The four figures create a slight diagonal, extending deeper and higher into space from the lower right (St. Jerome) towards the left side following the approach of church visitors. They are placed on a stage-like platform that is parallel to the picture plane. This platform projects horizontally in trapezoidal form toward the viewer, inviting access to the central group. Thus the viewer is beckoned by Magdalene, who reaches out in his/her direction, to emulate the actions of the genuflecting figure–Titian’s self-portrait in the guise of St. Jerome. The illusionistic manipulation of the architecture, and of the figures in front of it, dissolves the boundaries between the pictorial and the viewer’s space, between reality and illusion, thus de facto breaking the boundaries between spiritual and material reality. This commingling of real and fictive is further enhanced by the use of independent sculptural motifs surrounding the niche and the central group. The relation of the fictive sculptures and architecture may represent the most overt comment on the contemporary trend of disunity between figures and architecture in Venetian sculpture, represented by Vittoria and, in particular, the Zane Altar.
Reference: http://www.outpost-art.org/michelangelo-c-15_505_1007.html
http://history.hanover.edu/courses/art/111ren.html
http://www.outpost-art.org/titian-c-15_785_1023.html