It has always been difficult to define what a city is and now even more so as the boom in real-estate business has subjected it and its peri-urban areas to constant transformation. With this, segregation has also acquired a state of constant mutation and in fact, no longer seems to stabilize itself, as it did in the past, into recognizable spatial patterns. This has been happening in Chilean cities, just as it has in many other countries.Thus, the temptation of substituting physical-geographical and planimetric definitions, both of city and segregation. for others that emphasize processes, is understandable. Does this mean to say then. that the physical-spatial dimension of the city implicitly or explicitly lacks importance as neoliberal economists and urbanist devotees of structural-determinist approaches argue? It is true that the COVID-19 pandemic makes the feebleness of these approaches, which ignore the spatial aspect. patently clear, but this does not make it any less relevant to examine their theoretical setup, which we will do based on a critical review of the specialized literature and testimonies of specialists collected in a research project on segregation in three Chilean cities that we recently finished. We conclude these pages in the need to reinforce empirical research of the city and segregation. just as our attention to their subjective dimensions.