Numerous ethical theories have been proposed as a foundation of business ethics, and this often brings about appreciable perplexity. This article seeks to identify specific problems for a sound foundation of this discipline. A first problem is this multiplicity of ethical theories, each with its own metaethics, often accepted without a serious discussion of their philosophical grounds. A second problem is the fragmentation of theories; some centred on duties or obligations, others on consequences, virtues, or moral sentiments. In addition, some (...) theories focus on universal principles, while others take the singularity of each situation as their focal point. A third problem is that not every ethical theory covers the personal, organizational and societal dimensions of business ethics, and this introduces reductionism. These problems cannot be satisfactorily addressed through ‘ethical pluralism’, in which all theories are accepted, without falling into ethical relativism. ‘Ethical pragmatism’, which welcomes any ethical theory only on the basis of their practically, is also questioned. Furthermore, there is the problem of integrating ethics into business theory, which is often extrinsic to the economic function. After analysing these problems, the article concludes by exploring some proposals that might serve to build a sound and complete ethical theory which includes human goods (objective values), principles (or norms) and virtues. The necessity of reconsidering the human action for a closer integration of ethics into business theory is also suggested. (shrink)