He then provides examples of dubious criminal laws enacted by legislatures, in particular statutes on drugs possession and guns. The latter part of the book develops his theory, which establishes principles that should set limits (both external and internal to the criminal law) on what we can and should criminalize.

PREFACE
ACKNOWLEDGEMENTS
CHAPTER ONE: THE AMOUNT OF CRIMINAL LAW
II. How More Crimes Produce Injustice
III. The Content of New Offenses
IV. An Illustration of Overcriminalization
CHAPTER TWO: INTERNAL CONSTRAINTS ON CRIMINALIZATION
I. The General Part of Criminal Law
II. From Punishment to Criminalization
III. A Right Not to Be Punished?
IV. Malum Prohibitum
CHAPTER THREE: EXTERNAL CONSTRAINTS ON CRIMINALIZATION
I. Infringing the Right Not to be Punished
II. The Devil in the Details
III. Crimes of Risk-Creation
CHAPTER FOUR: ALTERNATIVE THEORIES OF CRIMINALIZATION
I. Law and Economics
II. Utilitarianism
III. Legal Moralism