This chapter deals with questions that many will regard as not only boring but also as unconnected to the real issues for decision in drug policy. Questions of definition and measurement strike most readers as procedural preliminaries to the discussion of important questions, as niceties to be relegated to a footnote or ignored altogether. But in drug control policy, what we do not define carefully we do not know, and what we do not know can cripple the capacity of policy to confront problems.

One of the hallmarks of an academic treatment of a subject is a concern with questions of definition and scope, with exactly those terms of reference that most people regard as obvious. So our preliminary insistence on the importance of definition here may mark us as hard-core academics. In fact, however, even those academics concerned with drug policy commonly ignore such matters, fearful perhaps that attention to them would be regarded as scholastic quibbling in the face of urgent social problems. But we think that it is worth time and attention to define the term drug and to discover to what extent different parties to the contemporary debate about drug policy define that key term in the same way. We shall show that a basic knowledge of the range of meanings assigned to key terms in the drug control debate is necessary to understanding the policy choices.