In his Iconologia, Cesare Ripa described “Error” as a blindfolded wayfarer who tries to find his way with the help of a stick. “Blind error”—such as we see it portrayed in an allegorical drawing by Antoine Coypel (1661-1722)—is always accompanied by ignorance. Error means losing one’s way, straying from the straight line; it is a condition that affects, in Ripa’s words, both our intellect and our body during our pilgrimage to happiness. Ripa plays on the ambiguity of the word “error,” which signifies both making a (moral) mistake and losing one’s way, or wandering without a direction, just as the characters of chivalric novels—the errant knights—who in their wandering often stray from the path of virtue. The epistemic and moral dimensions of error are, in Ripa’s words, clearly interdependent, as evident in his explanation of being blindfolded in symbolic terms: “when the light of intellect is darkened by the veil of worldly interest, one easily falls into error.” For Ripa, the stick represents the senses, a lower form of  knowledge than that of the intellect (symbolized by the eyes). Those who rely on the senses miss “the true causes of all things,” hence the author’s explicit connection between error and ignorance. In fact, Ripa’s depiction of “Ignorance” in the Iconologia depicts her as a blind woman walking barefoot through brambles, alongside the trodden path. Bypassing the many details of Ripa’s rich allegory of ignorance, it suffices here to remember that the author is not just describing the lack of knowledge, but also “the vice of ignorance,” which “is born out of contempt for knowledge.” A further, less explicit, but no less intriguing connection, can be made between error and doubt. In fact, “Doubt” is personified in the Iconologia as a young man walking in the dark carrying a stick and a lantern, objects that symbolize experience and reason respectively. These tools help the young and inexperienced man make his way through the darkness and overcome doubt, an “ambiguity of the mind concerning knowledge and, as a consequence, of the body concerning works.” While there are certainly multiple connections linking doubt, ignorance, and error, it is the lack of clear vision—an allusion to a want of clear intellect—that seems to be the common thread among these conditions. If the connection between error and ignorance is so straightforward that it seems almost platitudinous to articulate, the interrelation between error and doubt is perhaps less self-evident, but no less crucial. Doubt, or the inability to decide between two equivalent options due to the lack of recognizing the right choice, easily leads to error. Such a connection is made explicit in the title page of the Italian translation of one of the staples of the early modern European genre of “popular errors:” Thomas Browne’s Pseudodoxia epidemica (first published in 1646, lastly in 1672: see Paolo Cherchi’s essay in this volume). The full title reads Pseudodoxia epidemica, or enquiries into very many received tenents and commonly presumed truths. The Italian translation by Selvaggio Canturani (the Venetian Carmelite Arcangelo Agostini, 1660-1746), published in Venice in 1737, reads instead: Saggio sopra gli errori popolareschi ovvero esame di molte opinioni ricevute come vere, che sono false o dubbiose. Here error extends its realm from falsehood to doubt: everything that does not fall within the field of clear truth, in other words, appears to be potentially tainted by error. Yet it is also true that doubt and ignorance can correct an excess of dogmatic certainty, so that, as Montaigne writes in his essay On the Lame (Essays, 3, 11)—itself a veritable genealogy of error—“there is a sort of ignorance, strong and generous, that yields nothing in honour and courage to knowledge; an ignorance which to conceive requires no less knowledge than to conceive knowledge itself.” François Rigolot has spoken of the “Renaissance fascination with error,” noting how “most Renaissance humanists enjoyed themselves immensely in tracking down the incredible diversity of human and textual errors, before the seventeenth-century rationalist discourse clearly established the philosophical status of truth and falsehood.” In Rigolot’s view, “during the Reformation and Counter-Reformation theologians, philosophers, physicians, artists, and poets spent much of their time collecting, evaluating, denouncing, and celebrating various forms of misguided behaviour” (Rigolot 2004, 1221). Certainly the Middle Ages also recognized the ubiquitous presence of error in the various fields of learning and human behavior (Speer-Mauriège 2018). Undeniably, however, from the fifteenth century onwards one sees an explosion of philological castigationes, as well as lists of errors: religious, antiquarian, historiographical, and scientific. Examples include Giovanni Andrea Gilio’s published dialogue (1564) on the errors and “abuses” of painters (although the conversation recorded in the text allegedly took place in 1561), and two years later, a text devoted to “military deeds, inventions, and errors” by Bernardino Rocca (1515-1587). The impact of the printing press on the perception of error can be hardly overestimated. There is virtually no early modern book that does not invoke the reader’s cooperation in the correction of the many mistakes produced during the printing process, which served to heighten the perception of the diffusion of error. On the other hand, the press was a formidable instrument for the correction of mistakes. Such editorial power led Benedetto Altavilla to write in his Breve discorso intorno gli errori de calculi astronomici (A Brief Discourse on Errors in Astronomical Calculations, 1580) that the divine Majesty should be praised for granting authors countless privileges. Among them, Most great was the one he gave to Giovanni Lutemberg [sic] from Mainz in the year 1470, [that is] the art of the printing press, thanks to which all the deeds and ideas of men can be easily seen and understood by everyone […]. And now, thanks to this instrument, the inventors of the arts and the professors of sciences can share [their knowledge] with everyone. And those who read others’ works can, with equal ease, discover the errors they contain so that, contrasting them with their virtue and resorting to reason one gets to know the truth.