Lifeless winter without break: Ovid's exile works and the LiLa Knowledge Base
Authors: Aurora Alagni, Francesco Mambrini, Marco Carlo Passarotti (Università Cattolica del Sacro Cuore, 2024)
Topic: Sentiment, Emotion, Irony, Hate

Abstract
In this paper we describe the process of semi-automatic annotation and linking performed to connect two works by the Latin poet Ovid to the LiLa Knowledge Base. Written after Ovid's exile from Rome, the Tristia and the Epistulae ex Ponto mark the beginning of the ``literature of exile''. In spite of their importance, no lemmatized version existed and the two collections were not part of the major annotated corpora linked to LiLa. The paper discusses the workflow used to annotate and publish the works as Linked Open Data connected to the LiLa Knowledge Base. On account of their subject and the emotional tone attached to the theme of exile, the two works are particularly relevant for sentiment analysis. We discuss some results of a lexicon-based analysis that is enabled by the interlinking with LiLa. We use LatinAffectus, a manually-generated polarity lexicon for Latin nouns and adjectives, to perform Sentiment Analysis on the aforementioned works and interpret the (replicable) results by consulting and simultaneously enriching the available literary scholarship with new information. % AURORA % In this paper, we first demonstrate the necessity of interoperability, open access and continuous updating of linguistic resources produced for Latin. Specifically, we describe the process of publishing the morphologically annotated text of the Tristia and the Epistulae ex Ponto, two works written by Ovid during his exile on the shores of the Black Sea, in the LiLa Knowledge Base which follows the principles of the Linked Data paradigm and uses widely adopted ontologies to model the relevant information. Secondly, we show the potential of the hybrid approach promoted in the field of Computational Literary Studies, which allows addressing questions posed in literary criticism by using investigative tools developed in the field of computational linguistics. Specifically,

Introduction
The World Wide Web provides Latin scholars with a plethora of free, high-quality resources, issued from a long tradition of linguistic and philological study; many digital libraries, such as the Perseus Digital Library AUTHOR or the Digital Latin Library AUTHOR, supply electronic and often machine-actionable versions of some of the most studied texts in world literature. In the last years, the CIRCSE Research Center has developed the LiLa Knowledge Base with the objective of making the distributed knowledge about Latin texts interoperable through the application of the principles of the Linked Data paradigm AUTHOR. LiLa (presented below in sec. sec:lila) now includes a number of lexicons and annotated corpora. In particular, the Opera Latina LASLA corpus, a manually lemmatized and morphosyntactically annotated corpus of more than 1.5 million words mainly belonging to Classical Latin literature that was recently added to LiLa AUTHOR, has significantly expanded the textual heritage within the LiLa Knowledge Base, which now provides a Linked Open Data (LOD) compliant edition of many widely studied literary works. %, such as the Word Formation Latin (WFL) derivational lexicon AUTHOR and a few syntactically annotated corpora, including the Index Thomisticus Treebank (IT-TB) AUTHOR and the UDante Treebank AUTHOR. Furthermore, linking and included most of the works by Ovid, the author examined in this study. However, a significant portion of the author's production, namely the two works written during his relegatio in Tomis, modern Constantza, on the Romanian coast of the Black Sea, the Tristia and the Epistulae ex Ponto, was still unjustly missing. In its first part (section), this paper describes the Ovidian works already present in LiLa (subsection) and explains the process of annotating and publishing the digital editions of the aforementioned works in LiLa (subsection). Publius Ovidius Naso (anglicized as Ovid, 43 BCE - 17 CE) is arguably one of the most influential writers in the history of Western literature. His mythological poem in 15 books (the Metamorphoses, written between 2 and 8 CE) has been a crucial source of inspiration for artists like Dante, Shakespeare, or Titian. His body of elegiac poetry of erotic subject won him immense popularity during his life and afterwards. In spite of his importance, the work of Ovid is not represented in full neither in the LiLa network, nor in any other annotated corpora. The LASLA corpus provides only his earlier works (Ars Amatoria, Remedia Amoris, Medicamina, Amores, Heroids) and other poems (Fasti, Halieutica, Ibis), while the annotation of the Metamorphoses is listed as ``in progress''. Among the works that are utterly missing figure two of the last books of Ovid's career, the Tristia (``Sorrows'' or ``Lamentations'', written between 9--13 CE) and the Epistulae ex Ponto (``Letters from the Black Sea'', 12--17 CE, henceforth Epistulae) that were partly published after the poet's death. These two poetic collections center around Ovid's forced departure from Rome and exile to the town of Tomis (modern-day Constanța in Romania), at the furthest ends of the Roman empire. Despite his many attempts, Ovid would never come back from this ``utmost part of an unknown world'' (extremis ignoti partibus orbis, Tr. 3.3.3. ) nor was he ever restored to his previous status. % Although they do not clarify the reasons for the banishment imposed by the late emperor August himself, The two works are a fundamental source for the biography of the poet. Moreover, they are a foundational archetype of a peculiar sub-genre that is still influential in modern days, the ``exile literature'' AUTHOR. Ovid's exilic works were banished from libraries, and although they survived, were often judged unfavorably by the critics \cite[xxxvi]{green_2005}. The present study aims, in part, at revoking the ban that still seems to weigh on these Ovidian poetic collections, allowing them to enter the LiLa network. In what follows we describe how we prepared a lemmatized and part-of-speech (POS) tagged version of the two poems and how we linked this edition to the network of textual and lexical resources for Latin connected to LiLa. Our work fills the significant gap created by the absence of the exilic works of Ovid from the available annotated corpora. In addition, it also links to LiLa two collections of poems that, on account of their subject, foreground the emotional tone, and were successful in shaping the conventions of exilic literature; these works established the literary codification of the psychological reactions to banishment, within a veritable poetics of exile. Their content and historical relevance make them ideal candidates for a computationally based study on the sentiment analysis of literary texts.%, an application of Sentiment Analysis that is gaining more and more attention. The paper is structured as follows. Section sec:work reviews related work, with a specific focus on sentiment analysis within the field of Computational Literary Studies. Section sec:lila introduces the LiLa Knowledge Base and the language resources connected to it. Section sec:methodology describes the workflow followed for the annotation, publication and linking of the works. Section sec:sentiment discusses the type of knowledge that can be gained by combining the data from LatinAffectus, a prior polarity lexicon of Latin included in LiLa, and the newly prepared edition of the works, for a lexicon-based approach to their sentiment. Section sec:conclusion presents the conclusions and discusses plans for future work.

Conclusion
The work that we presented in the paper had two outcomes. Firstly, our LOD edition of Ovid demonstrates the benefits of interoperability among resources for Latin. Interoperability greatly facilitates the work of scholars, allowing them to benefit from lexicon, corpora, and NLP tools useful for every stage of their research through a single point of access. The LiLa project already provides a paradigm of this model, but to continue doing so, it requires constant integration. This is true not only for corpora, whose enrichment this paper testifies to. Despite the important results that SA conducted with LatinAffectus already provides for Ovid, there remains several ways for enhancing its performance. The coverage of LatinAffectus is extensive with regard to nouns and adjectives, as clearly demonstrated by its performance on the dataset discussed in this paper (see table tab:coverage). However, it is evident that a current limitation is its failure to account for the sentiment of verbs. This is why LatinAffectus, like the other linguistic resources available in LiLa, should not be regarded as a static resource, but rather as one that is continually evolving and being updated. Additionally, improvements could be made by accounting for syntactic phenomena such as polarity shifters AUTHOR and by taking into consideration the poetic nature of the text (e.g. by providing access to metrical information). In a broader sense, there is a lack of sufficient consideration for the context in which sentiment words are collocated. However, context-sensitive sentiment analysis is still in its early stages within NLP paper for an overview of state-of-the-art studies on context-sensitive sentiment analysis.}, and clearly, much work remains to be done to effectively incorporate context into sentiment analysis. The second outcome is in suggesting the undeniable potential of a hybrid approach, such as the one employed in this study, crossing literary criticism with the use of quantitative methods and computational resources. The theories developed within literary criticism and the investigative tools provided by computational linguistics can and should effectively collaborate, mutually enriching each other. In this specific context, the reflections developed within literary criticism regarding Ovid's exile works were crucial for interpreting the data derived from sentiment analysis. In turn, sentiment analysis was fundamental for confirming and deepening these observation, providing interpretable and reproducible data. If a classic is a book which has never exhausted all it has to say to its readers (as Calvino wrote \cite[5]{calvino_why_2009}), it is also because scholars are capable of interrogating it with new methods to address longstanding and unresolved questions.