Still more essential than color to appreciating the ways that Pontormo’s own grisailles work on the eye and the imagination is their powerful suggestion of animation. The distinction to be made is one between likeness and liveliness. Since antiquity, sculpture has confused and aroused the senses in its illusion of corporeality. The Virgilian expression spirantia signa, “breathing images,” permeated early writing on art, suggestive of mute stone rendered capable of speech and movement, suddenly pulsing with life. In Pontormo’s time, the language of Virgil came to be adopted by the likes of Baldessare Castiglione and Domizio Falcone. Literary references from Pliny and the Bible to Shakespeare likewise abound in references to the carnality of alabaster and marble. Few if any writers, however, can match Ovid in his vivid evocations of stone as living tissue. In Book IV of the Metamorphoses, the poet describes the vision that Perseus sees upon flying with the aid of his winged sandals above the shores of Ethiopia (fig. 67):
There, innocent, by Jove’s unjust decree
Condemned to suffer for her mother’s tongue,
Andromeda was pinioned to a rock.
When Perseus saw her, had a wafting breeze
Not stirred her hair, her eyes not overflowed
With trembling tears, he had imagined her
A marble statue [marmoreum ratus esset opus]. Love, before he knew,
Kindled; he gazed entranced; and overcome
By loveliness so exquisite, so rare,
Almost forgot to hover in the air. 
Momentarily, flesh and marble are confused, with almost dire consequences for the love-stricken hero.
The cult of images could also breed idolatry. In Girolamo da Treviso the Younger’s remarkable grisaille representing A Protestant Allegory of ca. 1538–44 (Hampton Court Palace, Royal Collection), the stone medium – and the life-endowing stony “seeds” of Deucalion and Pyrrha – have turned to weapons. The Four Evangelists hold aloft large rocks, their names inscribed upon them in Latinized form, and are about to cast the stones down onto a sprawled out figure of the pope (presumably intended to symbolize Paul III yet resembling Julius II). He lies atop two female figures, bearing inscriptions of their own upon their dress: Hypocrisy and Avarice. (fig. 69).
The furrowed brow, the strained neck veins, wide eyes and open mouth, preaching like that of Donatello’s Magdalene…The power and simmering intensity evidenced in Habakkuk’s entire sinewy frame is meant to astound. So real as to be lacking only speech, as the literary trope goes, the prophet nonetheless refused to respond to its maker, who damns his reticence. The prophet who, by contrast, speaks in his Book of Habakkuk, does so with a fiery tongue, warning the people of Jerusalem against moral dissipation – and, perhaps explaining his silent treatment with Donatello, berating sculptors for the making of “dumb idols.” “Woe betide him who says to the wood, ‘Wake up,’ / to the dead stone, ‘Bestir yourself’!,” he warns. He dares to take umbrage with God’s own unresponsiveness to his pleas: “How long, O Lord, have I cried to you, unanswered? / I cry ‘Violence!’, but thou dost not save.” At the destined hour, he presciently vows (in light of his stone surrogate’s place upon the campanile), “I will take up my position on the watch-tower.” While seemingly meant not only to instruct but entertain, Vasari revives the tradition of speaking sculptures – and sculptor as a second Deus artifex, addressing his own creations – while implicitly reminding of the spiritual peril of the same.
One of Pontormo’s earliest surviving sketches, now in the Uffizi, may reveal most tangibly the painter’s responsiveness to Donatello, showing as it does a male nude in exaggerated contrapposto that bears a striking resemblance to the older master’s bronze David for the Palazzo Medici (fig. 72). And while one might expected that the vivacità, or enlivening, of an image as “speaking likeness” depends on the presence of color, this was hardly the rule. Witness, for instance, the atmospheric veiling and pictorial effects animating Donatello’s Pazzi Madonna, executed in rilievo schiacciato (flat/squashed relief) (fig. 73).