Conceptions of Corporate Social Responsibility or Corporate Citizenship assign a new role to corporations as political actors which have to contribute to the common good. However, the question of whether such contributions should remain a voluntary act or have to be seen as an indispensable part of this new role of corporations is a matter of controversy. Based on the tenet of subsidiarity, as outlined in various social encyclicals, we will argue that corporations have to be seen as intermediate actors in society which bear concrete duties in a system of subsidiary societal task-sharing and should contribute to the common wealth beyond their pure business purposes.