For several decades now, intensive research has been carried out on the concept of a city that would be as environmentally friendly as possible, while simultaneously providing a high quality of life for its residents. As a result of this research, the concept of a sustainable city that addresses these challenges has been developed. The significance of this issue is evidenced by the fact that Sustainable Development Goal 11 is explicitly concerned with this topic. This paper aims to analyze the concept of a sustainable city from the perspective of the so-called ‘layered’ concept of man authored by Konrad Lorenz. It is based on the observation that the pace of biological evolution and that of the cultural evolution man undergoes differ significantly. While humans have adapted very quickly to urban living in their cultural layer, adaptation to city life in their biological layer has been very slow. The natural way of life pursued by the Homo sapiens was a hunter–gatherer lifestyle, which biological evolution had adapted the species to over hundreds of thousands of years. The changes associated with the Neolithic Revolution and the formation of the first cities took place about 11,000 years ago. Thus, not enough time has elapsed for humans to adapt biologically to their radically changed living conditions. The purpose of this paper is to look from a new perspective at the challenges faced by city dwellers, and in doing so, to identify the sources of these challenges and to arrange them in a hierarchy. An additional goal is to expand the argument for promoting certain elements of a sustainable city. Indeed, much seems to suggest that Lorenz’s concept offers a novel approach to looking at such urban issues as the challenges of overpopulation, man’s restricted access to nature, and the ever-increasing pace of life.