This book is a comprehensive study of the cognitive and material transformations that have been shaping Western societies and economies from the end of the 18th century through to the 1940’s. It analyses the ways in which ordinary daily activities (such as taking note, writing, copying, filing, counting, bookeeping and finaly computing datas) and the values they carry change in relationship to the development of the commercial sphere and in the management of the state. The aim is to insist on cognitive tasks or invisible ways of doing that does usually not appear in 'classical' narrative on technologies and to pay tribute to these thin or specific knowledge. From a more macrosocial or economic perspective, the idea is to look at "little tools of knowledge" and the way they shaped both the definition and scale of government, state, and business.