In this chapter I offer some reflections on the reconceptualization of Russian space and spatial development in the first half of the twentieth century. In particular, I focus on two scholars, D.M. Mendeleev and his disciple E.E. Sviatlovskii, who, in the late imperial and early Soviet periods respectively, sought to identify and map the forms and dynamics of Russian spatial change and to promote a rational, empirical, evolutionary approach to spatial planning and policymaking based on scientific method. In outlining their ideas and practice in the context of the spatial thinking of their time, and in tracing the rise and fall of their influence on state planning and policy, I hope to shed some light on the interactions of Russian science and government and the interrelations of culture and ideology, as well as on competing philosophies and visions of space and conflicting views of how space was to be analysed, apprehended, accounted for and acted upon.