This introduction presents an overview of key concepts discussed in the subsequent chapters of this book. The book offers a discussion of the general nature of rights. It explores the details of Raz's interest-based theory. Natural rights is simple nonsense: natural and imprescriptible rights, rhetorical nonsense, nonsense upon stilts. As the twentieth century draws to a close, it has become clear that the language of rights, often employed in political contexts and in debates over proposed social policies, has become detrimental to public deliberation about those policies. The most obvious alternative to the interest-based justification of rights is the duty-based justification, and the foremost version is described by Alan Gewirth. In the workplace, the notion of employee rights has become common and has been used in defense of more specific rights to a minimum wage and, in the face of corporate polygraph tests and drug-testing policies, to privacy and due process.