I WAS BORN IN Montbard, a small industrial town in the Côte d’Or, in the French region of Burgundy. The large metallurgical plant, no doubt the distant heir to Buffon’s forges, employed some 2,000 workers at the time, for a population of 6 or 7,000 in the commune. Its importance can still be gauged today by the fact that the TGV high-speed train from Paris to Dijon stops here at least twice a day, putting the small town within an hour of the capital. This major industrial site is the only one to have been created by the main Paris-Lyon-Marseille railway line (which initially passed through Dijon), making its own possible contribution to the theory of the structuring effect of transport routes on the location of economic activities. At the local level, the town exhibited a very distinctive spatial organisation, a real model of spatial zoning of urban activities and segregation of social categories whose representativeness I would discover later in the scientific literature by sociologists and geographers: the bourgeoisie and shopkeepers in the town centre, on the rocky hillock around which runs the Brenne valley, chosen as their residence by the Dukes of Burgundy as early as the 12th century, and by the naturalist Buffon in the 18th century; the factory, which still manufactures metal tubes, was separated from the town by the Canal de Bourgogne and the railway line; its employees’ homes were built on the southern slope of the valley, with the engineers’ detached houses close to the workplace, a little further up the road the semi-detached houses for the foremen’s families (including my parents’) and at the end of the road the multifamily dwellings for the workers, similar to the “corons” of mining towns. We walked a lot to getfor getting the smallest purchases in the town;, therefore, I covered four times a day the distance of one kilometre and a half to and from the primary school, crossing the railway line and then climbing the hill. As a child of the baby boom generation, I received a good education at school, encouraged by my parents and the local teachers. My career followed the only possible way open through the national education competitive examinations. Escaping the usual destinies allocated at that time to girls in the small industrial towns, I became a boarder student of the Ecole Normale de Filles that trained future teachers at Dijon. There, I could get fleeting but deep impressions from a beautiful regional capital; I greatly admired the architecture and the traces of Burgundy’s rich past while observing without much using a higher level of urban services. Entering the Ecole Normale Supérieure at Fontenay-aux-Roses was a double chance of getting a first salary and discovering Paris. It took me some time to decipher the most elementary codes of the capital, to perceive the assets of a large city, to measure its power and diversity, and to learn how to take advantage of the metropolitan facilities. Figure 1 - Prof. Pumain at the 6th European Colloquium on Theoretical and Quantitative Geography that she co-organised with Thérèse Saint- Julien at Chantilly (France) in September 1989. She writes: “Here, I invited Peter Allen (left) and Wolfgang Weidlich (right). The Brussels school of dissipative structures (Ilya Prigogine) and the Stuttgart group of synergetics (Herman Haken) met there for the first time.” This experience perhaps partly explains my attraction to geography, first as an opening onto the world, then as a scientific discipline. I hadn’t travelled much as a child, but the excursions organised by the ENS to Portugal, Ireland (my first plane trip in 1966), and Italy were excellent introductions to reading landscapes. My curiosity about the regularities of the urban hierarchy was aroused at university by lectures given by Pierre George, Philippe Pinchemel and Michel Rochefort. It was further sharpened during the preparation of a master’s thesis with Marie-Claire Robic on migration to and from French urban areas between 1954 and 1962, under the supervision of Philippe Pinchemel in 1968. I succeeded with the competitive examination called “aggregation” in 1969, which assured me of a career in secondary education. Still, I had caught the research bug, and a France-Québec grant enabled me to start a post-graduate thesis on the history of geography in Québec. Spending one year in Montreal and discovering geographies other than that of the French school was a rewarding experience. Reading a Master thesis by Leslie King initiated me about the gravity model that would have helped me so much in my previous analyses of interurban migrations; I also learnt there to use computers with software such as Fortran and SPSS. In 1970, I got a job as a lecturer at the Université Paris 1 Panthéon-Sorbonne, which confirmed my vocation for education and research. Figure 2 - A multilevel conceptualization of complex urban systems in space and time of social interactions The main question guiding my research becam