Cassius Dio's speeches and the collapse of the Roman Republic

This thesis argues that Cassius Dio used his speeches of his Late Republican and Augustan narratives as a means of historical explanation. I suggest that the interpretative framework which the historian applied to the causes and success of constitutional change can be most clearly identified in the speeches. The discussion is divided into eight chapters over two sections. Chapter 1 (Introduction) sets out the historical, paideutic, and compositional issues which have traditionally served as a basis for rejecting the explanatory and interpretative value of the speeches in Dio’s work and for criticising his Roman History more generally. Section 1 consists of three methodological chapters which respond to these issues. In Chapter 2 (Speeches and Sources) I argue that Dio’s prosopopoeiai approximate more closely with the political oratory of that period than has traditionally been recognised. Chapter 3 (Dio and the Sophistic) argues that Cassius Dio viewed the artifice of rhetoric as a particular danger in his own time. I demonstrate that this preoccupation informed, credibly, his presentation of political oratory in the Late Republic and of its destructive consequences. Chapter 4 (Dio and the Progymnasmata) argues that although the texts of the progymnasmata in which Dio will have been educated clearly encouraged invention with a strongly moralising focus, it is precisely his reliance on these aspects of rhetorical education which would have rendered his interpretations persuasive to a contemporary audience. Section 2 is formed of three case-studies. In Chapter 5 (The Defence of the Republic) I explore how Dio placed speeches-in-character at three Republican constitutional crises to set out an imagined case for the preservation of that system. This case, I argue, is deliberately unconvincing: the historian uses these to elaborate the problems of the distribution of power and the noxious influence of φθόνος and φιλοτιμία. Chapter 6 (The Enemies of the Republic) examines the explanatory role of Dio’s speeches from the opposite perspective. It investigates Dio’s placement of dishonest speech into the mouths of military figures to make his own distinctive argument about the role of imperialism in the fragmentation of the res publica. Chapter 7 (Speech after the Settlement) argues that Cassius Dio used his three speeches of the Augustan age to demonstrate how a distinctive combination of Augustan virtues directly counteracted the negative aspects of Republican political and rhetorical culture which the previous two case-studies had explored. Indeed, in Dio’s account of Augustus the failures of the res publica are reinvented as positive forces which work in concert with Augustan ἀρετή to secure beneficial constitutional change.

Ecology, physiology and performance in high-rate anaerobic digestion

The design demands on water and sanitation engineers are rapidly changing. The global population is set to rise from 7 billion to 10 billion by 2083. Urbanisation in developing regions is increasing at such a rate that a predicted 56% of the global population will live in an urban setting by 2025. Compounding these problems, the global water and energy crises are impacting the Global North and South alike. High-rate anaerobic digestion offers a low-cost, low-energy treatment alternative to the energy intensive aerobic technologies used today. Widespread implementation however is hindered by the lack of capacity to engineer high-rate anaerobic digestion for the treatment of complex wastes such as sewage. This thesis utilises the Expanded Granular Sludge Bed bioreactor (EGSB) as a model system in which to study the ecology, physiology and performance of high-rate anaerobic digestion of complex wastes. The impacts of a range of engineered parameters including reactor geometry, wastewater type, operating temperature and organic loading rate are systematically investigated using lab-scale EGSB bioreactors. Next generation sequencing of 16S amplicons is utilised as a means of monitoring microbial ecology. Microbial community physiology is monitored by means of specific methanogenic activity testing and a range of physical and chemical methods are applied to assess reactor performance. Finally, the limit state approach is trialled as a method for testing the EGSB and is proposed as a standard method for biotechnology testing enabling improved process control at full-scale. The arising data is assessed both qualitatively and quantitatively. Lab-scale reactor design is demonstrated to significantly influence the spatial distribution of the underlying ecology and community physiology in lab-scale reactors, a vital finding for both researchers and full-scale plant operators responsible for monitoring EGSB reactors. Recurrent trends in the data indicate that hydrogenotrophic methanogenesis dominates in high-rate anaerobic digestion at both full- and lab-scale when subject to engineered or operational stresses including low-temperature and variable feeding regimes. This is of relevance for those seeking to define new directions in fundamental understanding of syntrophic and competitive relations in methanogenic communities and also to design engineers in determining operating parameters for full-scale digesters. The adoption of the limit state approach enabled identification of biological indicators providing early warning of failure under high-solids loading, a vital insight for those currently working empirically towards the development of new biotechnologies at lab-scale.