Despite Brecht's emphasis on its centrality to his theatre, the concept of Gestus has only recently begun to receive more extensive analysis. This thesis contributes to the emergent research field through its exploration of several relatively unexplored areas. Firstly, it offers an account of the obscurity and scholarly neglect of the term 'Gestus' especially with regard to conceptual, linguistic and translation difficulties. Secondly, it presents original archival research into how Brecht applied his concept of Gestus to acting during his work in Berlin between 1949 and 1956. And thirdly, it investigates the role and relevance of Gestus in contemporary Anglo-American theatre. The reconstruction of Gestus is supplemented by a deconstruction of its potential and limitations as a tool for creating political theatre which resists oppressive discourses. With regard to 'potential', this study examines those moments when the Marxist Gestus presents an alternative to dominant tendencies within Western theatre. With regard to 'limitations', two main types of constraint are addressed. The first can be defined as the 'transgression' of the Marxist parameters within which gestic performance was constructed. The second constraint involves the 'suppression' of useful possibilities within and beyond the confines of those parameters. By means of the deconstructive strategy, gestic acting is exposed as a rich site of contradictions. Chapter One focuses mainly on the tensions between a bourgeois individualist and Marxist approach to gesture and an oscillation between the assertion of Gestus as a new Marxist aesthetic principle and as an old rhetorical device. Chapter Two highlights the contradiction between a mechanistic and dialectical materialism and the aesthetic interplay between the flux of montage and the stasis of analytical tableau. In Chapter Three the major tension explored is that between an avant-garde experimental and a deictic realist approach to gestural style. It is in the final two chapters that the role of gestic acting within contemporary theatre is investigated. Chapter Four argues that Gestus is the key to the difference between Brechtian and Stanislavskian modes of acting and demonstrates the exclusion of the Gestus in recent mainstream British theatre where performance often remains dominated by a Stanislavskian-derived system. Here the gestic principle is presented as continuing to challenge ahistorical essentialist approaches to performance. In Chapter Five the appropriation and modification of the Gestus of showing within materialist feminist theatre is discussed and Brecht's application of Gestus in Berlin is revealed as preempting many aspects of recent feminist theory and practice. The study concludes with a summary of the hierarchical binary oppositions - public/private, inscription/agency, demonstration/experience, stasis/flux, populist materialist/avantgarde - which it maintains underpin and contribute to the complex status of gestic acting as both a reactionary and progressive apparatus for societal transformation.