This course provides a foundation and an entry point into current debates in metaethics for students of philosophy. We will investigate questions such as: Do moral thoughts and moral sentences represent properties that exist in reality? If so, are these properties "natural" or sui generis? How can different theories of the subject matter of ethics account for moral knowledge? How can they account for the practical action-guiding role of moral judgments? We will emphasize some ways in which metaethics relates to other subfields of philosophy including metaphysics, philosophy of mind, philosophy of language, and normative ethics. By co-teaching the course, the instructors aim to counterpose some differing metaethical views and provoke active debate in the seminar, while also providing a textbook-supported introduction to the field. No prior knowledge of metaethics is assumed.