This chunky monograph on the Bossche School architect Jan de Jong (1917-2001). portrays a "forgotten genius. De Jong was already known in small circles as the most brilliant pupil of Dom Hans van der Laan (1904-1991), the Benedictine monk-architect who is now world famous for his architectural theory around the "plastic number. De Jong, however, increasingly withdrew from the world, so that his dozens of buildings and his opus magnum - his residence and office in Schaijk (1964/68) - also became forgotten. The monograph conclusively demonstrates De Jong's importance. He was already designing with the plastic number when dom Van der Laan himself was barely building. De Jong was also the first to give this conception of architecture a modern face and showed in a rich oeuvre how widely applicable the plastic number is. He even developed his own application of it, especially for urban planning. All this knowledge is now available to a wide audience for the first time The book 'Jan de Jong the monograph, part 1. Pioneer of plastic number' is written by architecture publicists Hilde de Haan and Ids Haagsma, authors of, among others, 'Buildings of plastic number' (Architext, 2010) and the guide 'Buildings of Jan de Jong' (Architext, 2012). For the monograph, they collaborated with Ir. Wim Ramselaar, who worked for De Jong during the crucial 1960s when the Bossche School flourished. The richly illustrated book gives a compelling picture of the quest that gripped De Jong throughout his life, and of the special relationship he had with Dom Hans van der Laan. He shared his passionate quest to find the secret of 'eternal beauty' and thus to raise architecture to a higher plane. A crucial discovery of Dom Van der Laan was the plastic number, a compositional tool to give buildings a powerful and beneficial coherence. This system of proportions is on the one hand mathematical in character but at the same time based on how our "spatial perception" works. It was precisely De Jong who was the first to translate dom Van der Laan's still fledgling theory into modern, austere forms, thus fully demonstrating its power. Thereafter, he was for many years the monk's antithesis, countering him more than others. He always remained faithful to his approach but in his own way, enriching its applicability in many ways. He did so especially also in the field of urban planning, for which De Jong had a special talent. An important part of the book consists of the "memories of Jan de Jong" by ir. Wim Ramselaar bi. This provides a vivid first-hand portrait of an extraordinary era. The book concludes with a reconstruction of Jan de Jong's urban planning theory, in which the authors have succeeded in processing the many piles of De Jong's manuscripts and drawings into a coherent vision that forms an intriguing addition to the architectural theory of dom Hans van der Laan.