A study of the effects upon design, principally architecture, of the Reformation and the associated rejection of imagery in worship. "The Plain Style" examines both the development of aesthetic theory and its practical applications in a number of different environments. The author traces the way in which ideas about simplicity, clarity and lack of ornamentation expressed themselves in art and architecture, and uses an extensive range of examples, from the British Isles, and particularly Northern Ireland, and from North America. In doing so he shows how Protestant, and especially iconoclastic Puritan, ideology influenced design. The external impact was reflected in an inner change in the psychic landscape, and its applications were therefore to be found well beyond the visual. The book, heavily illustrated with examples, shows how the effect can be found in areas like machinery design, and the impact of 'the Plain Style' on Puritan ideas and, for example, on Shaker furniture design. The study is divided into six chapters, moving from broader issues, such as an imageless worship and thought, to more specific areas. In his discussion of Ulster Protestant culture, Brett dismantles the conception that deep cultural contrasts exist between Protestants and Republicans. The author does not just depict the differences between Protestant and Republican cultures, but more importantly, the ways in which the seeming contrasts are manipulated. Indeed, it is through such a wide scope of topics that Brett emphasises a more creative Protestant lineage, in order to break down what Brett views as self-destructive models of thought within Protestant and Republican communities. While the literary and rhetorical aspects of the Plain Style have been studied, the author breaks new ground with this important book on the visual aesthetics of the Plain Style and makes a valuable contribution to cultural history and to the history of ideas.