Many of the arguments in the legalization debate involve empirical matters – either evaluative descriptions of the status quo or predictions about the likely consequences of a change in policy. But purely moral arguments also play a prominent role. Many prohibitionists assert that drugs should be banned because drug use per se is immoral. On the other side, many legalizers and decriminalizers argue that U.S. drug laws are hypocritical, or too draconian, or that they infringe on an individual's right to take drugs. Chapter 3 showed that nonempirical arguments were outnumbered by empirical assertions (not necessarily accurate) in American newspaper essays, but quantity says nothing about the force or conviction with which the arguments were believed or felt. Nor does quantity reveal the origins of the authors' views; empirical claims may serve as a means of bolstering an essentially values-based conviction. Additionally, it may be that the kinds of people who write op-ed essays (especially those that get published) are more enamored of, or at least more fluent in, empirical argumentation. Scrolling through the messages on any of the growing number of pro- and antidrug discussion groups on the Internet, one can find a much greater reliance on nonempirical, morals-based arguments.

The debate cannot be neatly parsed by distinguishing facts and values; philosophers and scientists have long rejected a strict fact-value dichotomy as untenable (see Cole, 1992). Values affect the selection, measurement, interpretation, and evaluation of research findings (MacCoun, 1998b).