In this chapter, we examine legitimacy in relation to recent debates on the philosophy of management and corporations that have emerged to deal with the decline of Protestant ethics. On this basis, we discuss the concepts of corporate citizenship and the good citizen corporations as recent efforts to respond to the problem of corporate legitimacy. From there, we discuss the contemporary use of the philosophy of Martin Heidegger to propose a critical reading of the search for legitimacy in the Western philosophy of management. Finally, we look at recent concepts of ontology and philosophy of sciences as present in contemporary debates.