The professionalisation of social work is examined using Germany as an example. The main aspects of the process are explored: professional qualifications, content aspects of professional work, resources allocated and their control, as well as empirical and theoretical research in social work. The evolution of approaches to aid motivation from ecclesiastical and Christian traditions of love for one's neighbour to institutionalised aid within the functioning of welfare states is analysed. The dynamics of approaches to the definition of neediness in order to prevent the development of social parasitism is studied, the historical continuity of forms of work with socially deprived groups is shown. The professionalization of social work is considered in socio-historical context: its connection with protest movements of neo-Marxist persuasion in 1960s and changes in the system of academic training of social work professionals with the introduction of Bologna system is analyzed. The material in this article is the result of many years of research, including participant observation by the authors. This text is the latest and the last article by Professor Horst Bossong, one of Germany's leading specialists in social work, social policy and administration. The article summarizes the author's long-standing interest in the history and philosophy of social work, which reflects major milestones in the spiritual evolution and economic development of contemporary European societies.