Jonah raises a very good point that bears emphasizing. All too often, advocates of a given policy position are unwilling to acknowledge that their policy may have negative consequences. This is intellectually sloppy and it can undermine one’s credibility. To use our current example, those of us who advocate an end to drug prohibition do ourselves no favors by ignoring the possibility that that aggregate drug use could increase. We may feel that the benefits of ending prohibition outweigh such risks, but it is disingenuous to pretend that such risks are absent. By the same token, defenders of drug prohibition should acknowledge that such policies increase violent crime, lead to more potent narcotics, and so on. Neither policy is perfect. Even the most ethical policy position will have its costs. All policy choices have both positive and negative consequences. Conservatives and libertarians are quick to point this out when puncturing the prescriptions advanced by our adversaries. We should all remember it when advancing prescriptions of our own.