What, fundamentally, is public management? This question is rarely answered clearly and confidently, whether by students of public management or academics in the field. This book answers this question, as its readers come to know why and how public management is a design-oriented professional discipline. The argument of the book is grounded in Herbert Simon’s ideas about design-oriented professional disciplines. However, Michael Barzelay’s argument runs counter to the idea that public management is a design science. It envisions the discipline as a professional practice that requires the thoughtful and skillful use of purposive theories of public organizations, along with reverse-engineered design-precedents, in problem-solving for public programs and organizations. How professional knowledge about public management is to be expanded through research and analytical synthesis is therefore a major thrust of the book’s overall argument. Michael Barzelay develops these arguments in a unique way, including guiding the reader through a fictional ”Public Management Gallery” featuring key contributions to purposive theorizing about public management as a professional practice. The book is an essential resource for those wishing to strengthen the professional practice of public management – and the discipline – through education and research immediately and for years to come.