The link between ornament and monstrosity was forged early in Western aesthetic discourse, when Horace summoned up his famous example of a combinatory creature in Ars poetica. Significantly, the monstrosities he warned against were not the result of extravagant embellishment; in fact Horace allowed that poets might occasionally choose to ‘sew on purple patches’ for ornamental effect. Instead, he pointed to an ornament gone rogue, one that refused to stay in its place, mute and deferential. Intermixing with and subverting the argument that it is supposed to enhance, ornament turns monstrous, transmogrified into a woman out of control – fair above, foul fish below: in short, a monster of confused parts. This is not simply a vivid example set by Horace to ridicule the excesses of artistic licence. Ars poetica deploys it as a sort of talisman to ward off a breach of social decorum. Monstrous ornament is not simply in bad taste; it threatens accepted societal norms and subverts cultural traditions and hierarchies.

The disruptive cultural agency of monstrous ornament warrants more attention. It is a function of ornament that has been largely overlooked, and represents a critically important way in which sixteenth-century Renaissance artists and intellectuals forged a modern sensibility. Their embrace of monstrous ornament turned the tables on Horace's aesthetics in order to do just what he feared: to challenge the status quo by scrambling narratives, bending genres, and rupturing settled argument.