As a young priest, Stefan Wyszyński observed the life of Włocławek workers – he taught them the Catholic social doctrine, presenting it as a remedy for exploitation by capitalists and communists. He was close to the working man and knew his ills. This experience, supported during a scientific trip by observing the life of workers in Western Europe, during which he looked at institutions dealing with working people, resulted in the post-war publication of the book The Spirit of Human Work. The book contained mature thoughts on the theoretical and Christian concept of work and worker. It gave answers to questions about how to work effectively and how to develop professionally and spiritually. The Spirit of Human Work became the basis for the later teaching of Cardinal Wyszyński, who repeatedly returned to the thoughts contained in this book, morally shaping subsequent generations. It turned out to be a humanistic and at the same time Christian position, which can also be read today.