Book excerpt: Preface by Kenneth Frampton Winner of the 1985 Architectural Critics Award for the best book published on architectural criticism over the past three years. Since the early 1950s, Alan Colquhoun's criticism and theory have acted as a conscience to a generation of architects. His rigor and conceptual clarity have consistently stimulated debate and have served as an impetus for the pursuit of new directions in both theory and practice. This collection of 17 of his essays marks a watershed in the development of architectural thinking over the past three decades, comprising a virtual "theory of Modernism" in architecture. In his earliest essays, Colquhoun concentrated on themes that for him comprised the modernist attitude in architecture - language, typology, and the structure of form. His stance since then has consistently been to try to relate these issues to current practice and to analyze the nature of architectural expression in relation to culture. Alan Colquhoun divides his time between England, where is is a principal in the firm of Colquhoun & Miller, and the United States, where he is Professor of Architecture at Princeton University. An Oppositions Book.