Louis Kahn (1901-1974), a practitioner of international modernism, sought the spiritual in his powerful forms and encouraged his students to seek the essential nature of architecture. His Philadelphia-based practice was responsible for the Richards Medical Research building in Philadelphia, Pennsylvania, the Yale Art Gallery extension in New Haven, the Kimbell Art Museum in Fort Worth and more. An essay by Kahn on his sources of inspiration is included as well as an interview with the architect on his working methods and his vision for the future of the profession.