Daniel Kahnemann’s magisterial Thinking, Fast and Slow is so full of insights it’s hard to pick out just one, but I was especially struck by the finding that the mind finds it hard to properly process information about benefits and harms. Information about benefits makes information about harms less believable, and vice versa. It’s as if the mind tries to divide objects into categories of “helpful” and “harmful,” and resists information that blurs that line.
That finding – which, I suppose, is simply a variation on the theme of cognitive dissonance – helps explain much of the discourse about drug policy, and especially about the therapeutic potential of abusable drugs. Whether some combination of the chemicals in cannabis, in some delivery vehicle, would prove safe and effective to treat some condition is not, as a logical matter, tightly bound to the question whether cannabis should be legal for use ad libitum, as alcohol is. Methamphetamine is therapeutically valuable and abusable; powdered rhinocerous horn is neither. So it ought to be possible to conduct two distinct debates: one about the pharmaceutical application of cannabis and the cannabinoids, the other about trading the pains of the current illicit market for the problems of a licit market in cannabis for non-medical use.
But the proponents of legal cannabis for non-medical use have successfully used the claim of medical efficacy as an entering wedge to legalization, and their opponents dim-wittedly enabled them to do so by blocking medical research and poking ignorant fun at “Cheech and Chong medicine.” The absurd result is that cannabis may well become legal for getting high before anyone in the U.S. is allowed to breed cannabis for medical research.
The psychological finding doesn’t make me feel any better about the blindness of pot advocates to its risks or of drug warriors to its benefits, but it does help me understand why members of each group could sincerely hold beliefs I find nonsensical, or why they might find polemical advantage in pretending to hold such beliefs. If admitting that cannabis in some form has medical utility makes it harder to persuade 14-year-olds not to get stoned all the time, I can make sense of parts the reluctance of parts of the prevention community to acknowledge the obvious, along with the reluctance of some enthusiastic anti-prohibitionists to admit that commercial availability and aggressive marketing will inevitably translate into higher rates of abuse.
But to understand is not, in my case, to forgive. If it requires some intellectual and moral discipline to acknowledge that actual policies have both advantages and disadvantages, then people who decide to engage in policy debates need to tone up their intellectual and moral muscles. You can’t keep running a republic if the public refuses the task of rational self-rule. Reasoned debate isn’t easy, or even pretty, but it beats the hell out of tyranny or civil war.