The overwhelmingly positive response to the introductory course on ethics since its first publication has now made a fourth edition possible, which fundamentally differs from the first. The revisions were significantly influenced by the experiences gained from using the book in teaching. This introductory course consists of six parts. After a preliminary clarification of what we mean by 'morality' and 'ethics,' three introductory contributions follow, explaining what moral problems are, how we can respond to them through argumentation, and how to weigh the relevant considerations. Subsequently, the main ethical theories are presented: virtue ethics, consequentialism, deontology, and contractualism. This is followed by discussions of the metaethical and action-theoretical foundations of ethics as well as their interrelations.