The Rationalist Reader incorporates the first documentary collection of writing on rationalism in twentieth century architecture, providing an accessible introduction to the subject, direct insight into the thinking of individual architects and their critics, and a current re-evaluation of the context from which they emerged.Key texts, including new translations, are placed within a wider historical and philosophical context by Alan Colquhoun, and considered with particular reference to nineteenth century architectural theory by Charles Rattray. Two separate documentary sections address the thinking behind rationalist architecture within the Modern Movement and ‘Rational Architecture’ as its counterpart within Neo-rationalism. German architectural historian Thilo Hilpert and Dutch architect and critic Henk Engel, provide introductions to the two periods, while Cambridge historian Nicholas Bullock contributes a linking piece focused on French experience post-war. A postscript samples retrospective views. The two sets of ‘documents’, identified with the periods 1920–1940 and 1960–1990, are arranged under comparative headings, allowing the reader to establish correspondences between the key themes of rationalist architecture.When the ‘historical’ experience of many young architects is confined to ‘masters’ and ‘iconic buildings’ located within the general flux of modernity, here the trajectory of rationalism in twentieth century architecture is seen to veer between a scientific methodology identified with generic models, and a formal paradigm of typological consistency. With its immediate philosophical origins in Enlightenment culture, the development of rationalism in nineteenth century architecture prefaced the volatility of later interpretations of rationalist architecture outlined and documented in this book.