The force of this passage derives from remarkable unanimity about the portraits of Titian from the sixteenth century to the twentieth century. Vasari comments on Titian's many portraits - though the comment might not have been intended to be entirely complimentary from a Florentine (e.g. Vasari, Le Vite, Testo VI.160). Reynolds in Discourse Eight, 1778, writes of 'the natural unaffected air of the portraits of Titian, where dignity, seeming to be natural and inherent, draws spontaneous reverence'( Reynolds, Discourses, p. 149). Kugler, ed. Eastlake, Handbook of the History of Painting, Part One, The Italian Schools, First Edition, in Murray's handbook of Painting in Italy, comments that 'princes and nobles honoured him as the first of portrait-painters'.
Ruskin at Works, 14.232 follows the consensus: the 'Venetian school of portraiture is headed by Titian and entirely right'. At Works, 22.331, however, Ruskin appears to suggesting that Titian gives only the 'look', rather than the reality. The assumptions underlying that remark seem close to views which were current in Florence in the sixteenth century. They stem from the influence of the third century neo-Platonist philosopher Plotinus, whose views were influential in late fifteenth and sixteenth century Florence. The Enneads of Plotinus were translated by Ficino in Florence in 1492, and Plotinus specifically excluded portraits from the definition of art (Porphyry, Life of Plotinus, and Plotinus Ennead V.8) on the grounds that they represented the appearances rather than the reality of things.
In Paolucci 'The Portraits of Titian', p. 101, Antonio Paolucci attributes Titian's success as a portrait painter to his ability to present both the appearance and the underlying 'ideal persona'.