In 1963 at the University of Cambridge, Peter Eisenman -- world famous for his Holocaust Memorial in Berlin (2005) and respected and feared by his colleagues for his intellectual acuity and quick-wittedness -- wrote a dissertation on the formal basis of modern architecture. In it, the architect confronts historicism with theory and the analysis of form, whose distinguishing features he regards as the foundation of architectural composition. Eisenman illustrates his observations with numerous, extremely precise hand drawings. This striking document, with its idiosyncratic photographs, fully deserves to be published here, for the first time, in a faithful reproduction of the original. In an afterword, Peter Eisenman discusses this remarkable starting point of his practical and theoretical work.