Today's society is characterized by its need for accessibility to a wide variety of activities, and thus the need for highly efficient ordered means of going from one place to another, of transporting goods and services. These means are hereafter referred to as systems of access. Systems of access throughout history have altered and influenced building form. Today's developments require major structures to provide for and order the different means of transportation into systems of access. This demand has created a new building form, The form contains the activities heretofore relegated to a two-dimensional surface or city floor, for example, pedestrian walks, automobile roads and parking areas, train tracks, and subway tracks. This building form also includes shops, restaurants, and various other facilities which depend upon direct accessibility to large numbers of people. The activities previously occupying major individual buildings on separate sites are located in and on this public structure and have a more individuated character. This new building form demonstrates clearly, the role of the individual building as a dependent part of the city. The elaborate systems of access demons Irate the role of such systems as basic organizing elements within the city. Together they demonstrate how major portions of our cities must be rebuilt, and the principles upon which new cities and new parts of our existing cities must be built. These principles are the thesis: --THE INDIVIDUAL BUILDING MUST BE CONSIDERED A DEPENDENT PART OF THE CITY. --THE INDIVIDUAL. BUILDING MUST BE CONSIDERED A PARTICIPANT IN SYSTEMS OF ACCESS THROUGH THE CONCEPT OF THE THREE-DIMENSIONAL CITY FLOOR. --THE INTEGRATION OF THE INDIVIDUAL BUILDING WITH SYSTEMS OF ACCESS REQUIRES CITY PLANNING. This thesis requires the recognition of the building of cities as a social activity directed toward social ends. The directing of the building of cities toward social ends requires the recognition of need and subsequent legislation enabling civic authorities to implement city planning. Because the city demands an integration with building, because it is the creation of an environment for man and a modification of the natural environment by man. THE CITY IS ARCHITECTURE.