Political ideas and even medical categories are bound up with institutions that have histories. In On Liberty, Mill took little account of this fact, except for a few comments about savagery as a historical childhood and his warning against the tendency toward a tyranny of popular feeling in advanced democracies. But in other writings, even he paid more attention to history. Against the rationalistic radicalism of his first master, Bentham, who called tradition “the authority of inexperience,” he eventually learned to balance the conservatism of Coleridge, who suggested that before denouncing an established institution or practice as irrational, we should ask, “What is the meaning of it?” The meaning of a practice, in the sense of its place in the life of a society, is inseparable from its development. Drug use may be one of those issues on which a page of history (or sociology) is worth more than a volume of logic.

Looked at as a series of incidents, the history of social and legal responses to drug use, especially in the last century and in the United States, sometimes seems melancholy and haphazard. It is easy to find inadequate pharmacology, inconsistent ad hoc responses based on poor information, indulgence of passions and prejudices, including racism, in response to drug scares, institutional self-aggrandizement by narcotics police, and a fair amount of hypocrisy and corruption.