This is a revised and translated edition of "Mot det Moderna Fornuftet", published in Sweden in 1992. It is a work on social and cultural history, and deals at a further level with the construction of thought processes and ideas in the late-18th century (or "mentality history"). Utilizing the diaries of John Hjerpe, a shopkeeper member of the lower-middle-class in Stockholm in the 1780s, the book explores a range of issues in modern cultural history. It focuses on the specific world of Hjerpe in terms of trade, social conditions and contemporary social life in Stockholm, and then proceeeds to discuss theoretical and methodological issues relating to how thought processes in the past were formed and articulated. The development of book production and marketing in Stockholm is analyzed, and there is also discussion of the diary evidence of Hjerpe pertinent to issues such as Europe, religious tolerance, secularization, and perceptions of the future.