Legal theory has many facets. There may be several approaches to the study of law. Philosophical, sociological, or political approaches are just some of them. This book is a philosophical introduction to the most fundamental issues of legal theory, such as what the law is, when it exists, and how it binds. Despite its claim to be an introduction, the book is more than a collection of information. It is discursive. The book makes and defends several original claims about the nature of legal norms and legal systems. These claims and defenses are more or less final. Other discussions prioritize asking critical questions over finding definitive answers. It is hoped that the air of uncertainty created by these critical questions will stimulate the reader`s thinking.