Argument & Computation

Identifying rhetorical figures with marginal to non-existent lexico-syntactic signatures poses significant challenges for computational approaches reliant upon structural definitions or descriptions. One such figure is prolepsis ( π ρ ó λ η ψ ι ς ), which this essay charts out in some detail, addressing the challenges and the benefits of rendering such figures computationally tractable through the use of argument schemes with attention to metadiscursive or macro-discursive norms offered by pragma-dialectical traditions.

Litotes, often confused with meiosis and understatement, has long suffered neglect. By comparing synonymous key words in previous definitions, this essay defines litotes as “a trope in which an affirmative is expressed by the negation of its opposite,” and for the first time classifies litotes into three subtypes based upon Aristotle’s study of opposition: contradictory, contrary and relative. Focusing particularly on the strong contradictory type of litotes and its realization in The Analects of Confucius, with its nearly one hundred double negation litotes, we find they prominently serve the logical functions of achieving high probability, providing a sophisticated major premise, and elaborating strict definitions. Further, the essay argues that this strong argumentative function in logic leads to litotes’ epistemic power, a promising dimension for future research.

This paper surveys ontological modeling of rhetorical concepts, developed for use in argument mining and other applications of computational rhetoric, projecting their future directions. We include ontological models of argument schemes applying Rhetorical Structure Theory (RST); the RhetFig proposal for modeling; the related RetFig Ontology of Rhetorical Figures for Serbian (developed by two of the authors); and the Lassoing Rhetoric project (developed by another of the authors). The Lassoing Rhetoric venture is interesting for its multifaceted approach to linguistic devices, prominently including rhetorical figures, but also RST relations and stylistic models, like the use of historic present. This application takes a natural language text input and uses syntactic parsing tools to produce a knowledge base of linguistic entities using references to an OWL ontological framework, locating these devices using Semantic Web Rule Language (SWRL) logic rules. The paper also reports on a similar approach in research into detecting ironic tweets in a Serbian twitter corpus. The rhetorical schemes used for argument mining are also presented, as well as some suggestions for novel argument schemes based on the ontological approach to rhetorical figuration.

The generalised, automated reconstruction of the reasoning structures underlying persuasive communication is an enormously challenging task. While this work in argument mining is increasingly informed by the rich tradition of argumentation studies outside the computational field, the rhetorical perspective on argumentation is thus far largely ignored. To explore the application of rhetorical insights in argument mining, we conduct a pilot study on the connection between rhetorical figures and argumentation structure. Rhetorical figures are linguistic devices that perform a variety of functions in argumentative discourse. The textual form of some of these figures is easy to identify automatically, such that an established connection between the figure and a preponderance of argumentative content would improve the performance of argument mining techniques. Furthermore, the automated mining of rhetorical figures could be used as an empirical, corpus-based testing ground for the claims made about these figures in the rhetorical literature. In the pilot study, we explore the connection between eight rhetorical figures the forms of which we expect to be relatively easy to identify computationally, and argumentation structure (concretely, we consider the six schemes ‘anadiplosis’, ‘epanaphora’, ‘epistrophe’, ‘epizeuxis’, ‘eutrepismus’, and ‘polyptoton’, and the two tropes ‘antithesis’ and ‘dirimens copulatio’, and relate their occurrences to relations of inference and conflict). The data of the study is collected in the MM2012c corpus of 39,694 words of argumentatively annotated transcripts from the BBC Radio 4’s Moral Maze discussion program. We show that some of the figures indeed correspond to passages of high argumentative density, relative to the text as a whole.