To Haller the Bernese patrician, rhetoric as the art of persuasion still had a public function. He saw rhetoric and literature as brother 'and sister, both offspring of wit or the imagination, and their primary function as the promotion of truth and virtue rather than mere entertainment. The thesis falls into two parts. The first part deals with aesthetic problems: that is, with the relationship between form and content (verba' and 'res'), imagination and judgment ('ingenium' and 'iudicium'), and wit and sublimity. The second part extends the dispute between wit and sublimity into the wider arena of morality, politics_and religion. The first section examines Haller's Neo-Platonic mistrust of rhetoric as a perversion of the truth,· a mistrust based on his scientific and religious background. His elevation of content over form leads to an examination of the concept of sublimity, and in particular, of sublime simplicity, where truth and grandeur of content are conveyed in the simplest words. I try to place Haller's own elliptical brevity in this context, noting that the directness and immediacy Breitinger admires in it are also a feature of sublime simplicity. There is also some examination of the contrast between flawed sublimity and faultless mediocrity which so preoccupied German criticism from the 1740s onwards. Section Two examines the question of the poet's moral character, or the concept of 'vir bonus'. A poet may be a skilful manipulator of his audience's emotions, yet remain uncommitted to the truth or morality. I examine ·the proposition that great men, whether of literature, politics, or arms, only truly flourish in the relative freedom of a republic, taking Haller's Swiss republicanism into account. I try to analyse Haller's concept of virtue as loyalty bo the community rather than to one's own self-glorification. The final chapter assesses his attitude towards contemporary writers, most notably the French, in this light.