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Classical economic theory conceives space as a resource, an obstacle and the basis of international specialisation, but marginalist theory has reduced its role. Spatial economic theory developed according to hypotheses formulated at the beginning of the nineteenth century. The 1930s discovered national scale and growth through macroeconomics as well as the role of information through market imperfections. During the 1950s and 60s, spatial economics and economic geography developed upon these foundations theories such as central place and polarised growth, and explained the opposition between central areas and peripheries. A new sensitivity to scale and external economies as well as to the costs of information and commutation characterised the last generation. Progress is now taken into account. Space differentiates knowledge and may either promote or prevent innovation ; more attention should be devoted to issues surrounding the economics of proximity.