The Polipticum quod appellatur Perpendiculum by Atto, bishop of Vercelli (924-960 ca.), is known among historians of the post-carolingian kingdom of Italy mainly for its reputation of being a near-unsolvable enigma.
The text has been preserved in a single manuscript (Ms. Vat. Lat. 4322) on which it appears in two versions: the first one is ciphered using scinderatio technique as well as the substitution of each single term with an extremely rare synonym. The second one consists in a partial “decoding” of the first: the sequence of the words is rearranged, while several interlinear glossae give an explanation of most terms. Yet it is the content of Atto’s work, even more than its singular form, which gives rise to the greatest questions: through a long series of obscure allusions the author portrays the struggle between usurper kings, legitimate kings and different ranks of aristocracies, without divulging any single name or any clear, specific reference. This entangled account is followed by theoretical argumentation, the interpretation of which is problematic, about the facts shown in the first part. Moreover, the source is preceded by a most enigmatic “dedicatory epistle”, subject to the same ciphering as the text, with which Atto sends his work to an anonymous addressee.
This study aims to answer the basic questions regarding the source still awaiting solution: what is the Perpendiculum? Under which circumstances and for what purpose has it been written? Why did the author decide to cipher the text? And who is the anonymous recipient?
The analysis of the rhetorical structure and lexicon allows to recognize its nature of political oratio with which bishop Atto, using sharp prophetic oratory (inherent in the title: “The Plumb-line”) intends to persuade the mystery addressee that usurpation of a crown already held by a legitimate king is not only a moral but also a political mistake. The “usurpation” which Atto hopes to avoid with this elaborate call is the one that would return Otto I to the Italian throne, chasing off Berengar II for a second time: internal references allow us to date the composition between 953 and 960, thus capturing the bishop’s political view on events that took place during the second quarter of the tenth century. The Perpendiculum is not only one of the very few anti-ottonian voices preserved, but also an original point of view on the upheaval of aristocracy’s ranks witnessed by Atto himself, especially during the reign of Hugh of Arles, protagonist of the first part of the text.
The bishop’s work in combination with contemporaneous sources and examined with the support of the most recent Italian and international historiography allows us to paint a detailed picture of Italian political history in the first half of tenth century, of its functioning and actors.
The book concludes with the formulation of a hypothesis about the identity of the anonymous recipient, and its appendices provide the transcript of unedited glossae of Vatican manuscript and an Italian translation of the source.
PRIMA PARTE - CHE COS’È IL PERPENDICULUM?
1. MANOSCRITTO E ATTRIBUZIONE : Un unico testimone - La biblioteca di Attone - L’evidenza materiale - L’arrivo alla Biblioteca Apostolica Vaticana - La diatriba de Attonibus e i dubbi sulla paternità dell’opera.
2. STRUTTURA RETORICA: Argumentum e dispositio dell’opera - Exordium - Narratio - Argumentatio e conclusio - Struttura retorica e struttura logica.
3. CONTESTO E FINALITÀ : Il primo usurpatore - Il re presente - Il nuovo usurpatore - L’usurpazione da scongiurare - Contesto e finalità.
SECONDA PARTE - IL FILO A PIOMBO
4. NARRATIO: L’ORIGINE DEL CHAOS: L’usurpazione: cronaca, paradigma, prefigurazione - Le conseguenze dell’usurpazione: il regno di Ugo di Provenza - La debolezza iniziale - Da re di nome a tiranno di fatto - L’eliminazione di Anscario II - L’apoteosi dell’usurpatore - La struttura della prima parte della narratio - Il ‘nuovo ordine’ e la caduta dell’usurpatore - La caratterizzazione attoniana dell’usurpatore
5. NARRATIO: LA QUAESTIO POLITICA : L’annullamento dell’autorità: l’assenza di Lotario II - Maiores e minores - La giusta repressione: Berengario II - La caratterizzazione del ‘re presente’ - L’illusione dei proceres: Ottone di Sassonia - La caratterizzazione dell’usurpatore futuro.
6. ARGUMENTATIO E CONCLUSIO : Percontatio: la parola agli avversari - Invettiva - Confutazione - Un’estensione significativa: la perdita della legittimità - La legittimità come modello assoluto - La cornice escatologica: gloria mondana e gloria ultraterrena - L’ordine ideale: la preghiera finale - La cessazione del chaos.
TERZA PARTE - ARISTOCRAZIE, RE, VESCOVO
7. LESSICO POLITICO: I PROTAGONISTI DELLA LOTTA PER LA GLORIA MONDANA: Il lessico - L’uso dei termini connotanti.
8. ARISTOCRAZIE E RE: L’eliminazione dei tribuni - I milites traditori - La genuina prosapia - La fine di re Ugo - Maiores e minores.
9. IL RUOLO POLITICO DEL VESCOVO ATTONE: Il De pressuris ecclesiasticis - Le lettere
CONCLUSIONI – APPENDICI - BIBLIOGRAFIA - INDICE ANALITICO