Computer and networks like the Internet have transformed our perception of space. They are also synonymous with the development of a new type of society, often characterized as informational. Although its full scope has become visible only in the past decades, the digital revolution is rooted in a relatively long history. The massive expansion of information at the beginning of the twentieth century, or the intensive use of computer-aided simulations during the Cold War, represent key episodes of this history. The course will study these episodes as an introduction to the contemporary questions that the digital revolution raises in the domain of urban and architectural planning and design.A first set of questions regards the reshaping of sociability that is taking place under our eyes. What are its consequences on the way cities and building are conceived? Should one design for cyborgs? Actually, one of the major hypothesis of this lecture course is that the reshaping of sociability is rooted in a series of fundamental shifts in the definition of the individual. Some of these shifts occur as early as the beginning of the twentieth century. Others have become visible more recently. Any inquiry regarding the nature of digital culture raises inevitably questions of an anthropological and even philosophical nature regarding the contemporary subject.The use of the computer by planners and architects raises another set of interrogations regarding the consequences of such an evolution. Does it jeopardize the physical basis of architectural design as critics like Kenneth Frampton have put it? What is taking place under our eyes is perhaps a radical transformation of our definition of materiality, rather than a mere abandon of it by an architectural discipline oblivious of its foundations.