This collection discusses different aspects of the COVID-19 pandemic, which began in December 2019 in Wuhan, China, brought together under the slogan of "social worlds". It is a book dedicated to thinking a posteriori about the implications and consequences of the pandemic, bearing in mind that it was a challenge (political, social, economic and philosophical) that tested the limits of human nature and the condition of humans in a world whose logic seems to slip away.In this sense, this volume brings together different approaches to this topic, ranging from philosophy to sociology, and from politics to social work, thus constituting an original work on such a delicate issue.